2011 |
Takasaki, Yuka; Watanabe, Masaki; Yukawa, Hiroshi; Sabarudin, Akhmad; Inagaki, Kazumi; Kaji, Noritada; Okamoto, Yukihiro; Tokeshi, Manabu; Miyamoto, Yoshitaka; Noguchi, Hirofumi; Umemura, Tomonari; Hayashi, Shuji; Baba, Yoshinobu; Haraguchi, Hiroki. Estimation of the Distribution of Intravenously Injected Adipose Tissue-Derived Stem Cells Labeled with Quantum Dots in Mice Organs through the Determination of their Metallic Components by ICPMS. Journal Article In: Analytical Chemistry (Washington, DC, United States), vol. 83, no. 21, pp. 8252–8258, 2011, ISSN: 0003-2700. @article{Takasaki2011a,
title = {Estimation of the Distribution of Intravenously Injected Adipose Tissue-Derived Stem Cells Labeled with Quantum Dots in Mice Organs through the Determination of their Metallic Components by ICPMS.},
author = {Takasaki, Yuka and Watanabe, Masaki and Yukawa, Hiroshi and Sabarudin, Akhmad and Inagaki, Kazumi and Kaji, Noritada and Okamoto, Yukihiro and Tokeshi, Manabu and Miyamoto, Yoshitaka and Noguchi, Hirofumi and Umemura, Tomonari and Hayashi, Shuji and Baba, Yoshinobu and Haraguchi, Hiroki.},
doi = {10.1021/ac202053y},
issn = {0003-2700},
year = {2011},
date = {2011-01-01},
journal = {Analytical Chemistry (Washington, DC, United States)},
volume = {83},
number = {21},
pages = {8252--8258},
publisher = {American Chemical Society},
abstract = {Adipose tissue-derived stem cells (ASCs) have shown promise in cell therapy because of their ability to self-renew damaged or diseased organs and easy harvest. To ensure the distribution and quantification of the ASCs injected from tail vein, several whole-body imaging techniques including fluorescence optical imaging with quantum dots (QDs) have been employed, but they may suffer from insufficient sensitivity and accuracy. Here, the authors report quant. distribution of ASCs in various organs (heart, lung, liver, spleen, and kidney) of mice, which were i.v. injected with QDs-labeled ASCs (QDs-ASCs), through the detection of QDs-derived metallic components by inductively coupled plasma mass spectrometry (ICPMS). For accurate and precise detn., each organ was harvested and completely digested with a mixt. of HNO3 and H2O2 in a microwave oven prior to ICPMS measurement, which was equipped with a microflow injection system and a lab.-made capillary-attached micronebulizer. After optimization, 16 elements including major components (Cd, Se, and Te) of QDs and essential elements (Na, K, Mg, Ca, P, S, Mn, Fe, Co, Cu, Zn, Se, Sr, and Mo) were successfully detd. in the organs. As compared to untreated mice, QDs-ASCs-treated mice showed significantly higher levels of Cd and Te in all organs, and as expected, the molar ratio of Cd to Te in each organ was in good agreement with the molar compn. ratio in the QDs. This result indicates that the increment of Cd (or Te) can be used as a tracer for calcg. the distribution of ASCs in mice organs. As a result of the calcn., 36.8%, 19.1%, 0.59%, 0.49%, and 0.25% of the total ASCs injected were estd. to be distributed in the liver, lung, heart, spleen, and kidney, resp. [on SciFinder(R)]},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Adipose tissue-derived stem cells (ASCs) have shown promise in cell therapy because of their ability to self-renew damaged or diseased organs and easy harvest. To ensure the distribution and quantification of the ASCs injected from tail vein, several whole-body imaging techniques including fluorescence optical imaging with quantum dots (QDs) have been employed, but they may suffer from insufficient sensitivity and accuracy. Here, the authors report quant. distribution of ASCs in various organs (heart, lung, liver, spleen, and kidney) of mice, which were i.v. injected with QDs-labeled ASCs (QDs-ASCs), through the detection of QDs-derived metallic components by inductively coupled plasma mass spectrometry (ICPMS). For accurate and precise detn., each organ was harvested and completely digested with a mixt. of HNO3 and H2O2 in a microwave oven prior to ICPMS measurement, which was equipped with a microflow injection system and a lab.-made capillary-attached micronebulizer. After optimization, 16 elements including major components (Cd, Se, and Te) of QDs and essential elements (Na, K, Mg, Ca, P, S, Mn, Fe, Co, Cu, Zn, Se, Sr, and Mo) were successfully detd. in the organs. As compared to untreated mice, QDs-ASCs-treated mice showed significantly higher levels of Cd and Te in all organs, and as expected, the molar ratio of Cd to Te in each organ was in good agreement with the molar compn. ratio in the QDs. This result indicates that the increment of Cd (or Te) can be used as a tracer for calcg. the distribution of ASCs in mice organs. As a result of the calcn., 36.8%, 19.1%, 0.59%, 0.49%, and 0.25% of the total ASCs injected were estd. to be distributed in the liver, lung, heart, spleen, and kidney, resp. [on SciFinder(R)] |
Shu, Shin; Kobayashi, Hiroharu; Kojima, Norihisa; Sabarudin, Akhmad; Umemura, Tomonari. Preparation and characterization of lauryl methacrylate-based monolithic microbore column for reversed-phase liquid chromatography. Journal Article In: Journal of Chromatography A, vol. 1218, no. 31, pp. 5228–5234, 2011, ISSN: 0021-9673. @article{Shu2011,
title = {Preparation and characterization of lauryl methacrylate-based monolithic microbore column for reversed-phase liquid chromatography.},
author = {Shu, Shin and Kobayashi, Hiroharu and Kojima, Norihisa and Sabarudin, Akhmad and Umemura, Tomonari.},
doi = {10.1016/j.chroma.2011.05.104},
issn = {0021-9673},
year = {2011},
date = {2011-01-01},
journal = {Journal of Chromatography A},
volume = {1218},
number = {31},
pages = {5228--5234},
publisher = {Elsevier B.V.},
abstract = {Poly(lauryl methacrylate-co-ethylene dimethacrylate) monoliths were in situ synthesized within the confines of a silicosteel tubing of 1.02 mm i.d. and 1/16'' o.d. for microbore reversed-phase HPLC. To obtain practically useful monoliths with adequate column efficiency, low flow resistance, and good mech. strength, some parameters such as total monomer concn. (%T), crosslinking degree (%C) and polymn. temp. were optimized. High-efficiency monoliths were successfully obtained by thermal polymn. of a monomer mixt. (40%T, 10%C) with a binary porogenic solvent consisting of 1-propanol and 1,4-butanediol (7:4, vol./vol.) at a high temp. of 90°. The morphol. and porous structure of the resulting monoliths were assessed by scanning electron microscope (SEM) and inverse size exclusion chromatog. (ISEC), while the column performance was evaluated through the sepns. of a series of alkylbenzenes in acetonitrile-water (50:50, vol./vol.) eluent. At a normal flow rate of 50 $mu$L/min (corresponding to 1.66 mm/s), the optimized monolithic columns typically exhibited theor. plate nos. of 6000 plates/10 cm-long column for amylbenzene (k > 40), and the pressure drop was always less than 1 MPa/10 cm. The monoliths, which were chem. anchored to the tube inner wall surface using a bifunctional silylation agent, exhibited adequate mech. strength of up to 12-13 MPa, and were properly operated at 10 times higher flow rate than normal, reducing the sepn. time to one tenth. The lauryl methacrylate-based monolithic column was applied to a rapid and efficient sepn. of ten common proteins such as aprotinin, RNase A, insulin, cytochrome c, trypsin, transferrin, conalbumin, myoglobin, $beta$-amylase, and ovalbumin in the pptn.-redissoln. mode. Using a linear CH3CN gradient elution at a flow rate of 500 $mu$L/min (10-times higher flow rate), 10 proteins were baseline sepd. within 2 min. [on SciFinder(R)]},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Poly(lauryl methacrylate-co-ethylene dimethacrylate) monoliths were in situ synthesized within the confines of a silicosteel tubing of 1.02 mm i.d. and 1/16'' o.d. for microbore reversed-phase HPLC. To obtain practically useful monoliths with adequate column efficiency, low flow resistance, and good mech. strength, some parameters such as total monomer concn. (%T), crosslinking degree (%C) and polymn. temp. were optimized. High-efficiency monoliths were successfully obtained by thermal polymn. of a monomer mixt. (40%T, 10%C) with a binary porogenic solvent consisting of 1-propanol and 1,4-butanediol (7:4, vol./vol.) at a high temp. of 90°. The morphol. and porous structure of the resulting monoliths were assessed by scanning electron microscope (SEM) and inverse size exclusion chromatog. (ISEC), while the column performance was evaluated through the sepns. of a series of alkylbenzenes in acetonitrile-water (50:50, vol./vol.) eluent. At a normal flow rate of 50 $mu$L/min (corresponding to 1.66 mm/s), the optimized monolithic columns typically exhibited theor. plate nos. of 6000 plates/10 cm-long column for amylbenzene (k > 40), and the pressure drop was always less than 1 MPa/10 cm. The monoliths, which were chem. anchored to the tube inner wall surface using a bifunctional silylation agent, exhibited adequate mech. strength of up to 12-13 MPa, and were properly operated at 10 times higher flow rate than normal, reducing the sepn. time to one tenth. The lauryl methacrylate-based monolithic column was applied to a rapid and efficient sepn. of ten common proteins such as aprotinin, RNase A, insulin, cytochrome c, trypsin, transferrin, conalbumin, myoglobin, $beta$-amylase, and ovalbumin in the pptn.-redissoln. mode. Using a linear CH3CN gradient elution at a flow rate of 500 $mu$L/min (10-times higher flow rate), 10 proteins were baseline sepd. within 2 min. [on SciFinder(R)] |
Sabarudin, Akhmad; Umemura, Tomonari; Motomizu, Shoji. Chitosan functionalized with di-2-propanolamine - Its application as solid phase extractant for the determination of germanium in water samples by ICP-MS. Journal Article In: Microchemical Journal, vol. 99, no. 1, pp. 34–39, 2011, ISSN: 0026-265X. @article{Sabarudin2011,
title = {Chitosan functionalized with di-2-propanolamine - Its application as solid phase extractant for the determination of germanium in water samples by ICP-MS.},
author = {Sabarudin, Akhmad and Umemura, Tomonari and Motomizu, Shoji.},
doi = {10.1016/j.microc.2011.03.004},
issn = {0026-265X},
year = {2011},
date = {2011-01-01},
journal = {Microchemical Journal},
volume = {99},
number = {1},
pages = {34--39},
publisher = {Elsevier B.V.},
abstract = {Cross-linked chitosan was chem. modified with di-2-propanolamine via an arm of chloromethyloxirane (CCTS-DPA resin). The adsorption behavior of the resin towards 62 elements was examd. using a mini-column pretreatment method, and the collected elements were eluted with 1 mol L-1 HNO3 before measurement by inductively coupled plasma-mass spectrometry (ICP-MS). The CCTS-DPA resin can adsorb several metal cations and several oxoanionic elements at appropriate pH. However, di-2-propanolamine (DPA) attached to cross-linked chitosan (CCTS) showed excellent ability and selectivity for the adsorption of Ge at pH 6 to 9. The adsorption capacity of the resin for Ge (IV) is 106 mg g-1 resin, whereas the adsorption rate const. was 9.82 × 10-2 min-1. Through the column treatment, alkali and alk. earth matrixes in river water and seawater matrixes could be completely removed. The resin can also successfully remove chloride and Se that can interfere with the direct detn. of Ge by ICP-MS. The applicability of the CCTS-DPA resin was further demonstrated for the collection/preconcn. of Ge in environmental H2O samples and its detn. by ICP-MS. The concns. of Ge in tap H2O, river water and seawater samples were found at 0.011-0.022 $mu$g L-1. [on SciFinder(R)]},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Cross-linked chitosan was chem. modified with di-2-propanolamine via an arm of chloromethyloxirane (CCTS-DPA resin). The adsorption behavior of the resin towards 62 elements was examd. using a mini-column pretreatment method, and the collected elements were eluted with 1 mol L-1 HNO3 before measurement by inductively coupled plasma-mass spectrometry (ICP-MS). The CCTS-DPA resin can adsorb several metal cations and several oxoanionic elements at appropriate pH. However, di-2-propanolamine (DPA) attached to cross-linked chitosan (CCTS) showed excellent ability and selectivity for the adsorption of Ge at pH 6 to 9. The adsorption capacity of the resin for Ge (IV) is 106 mg g-1 resin, whereas the adsorption rate const. was 9.82 × 10-2 min-1. Through the column treatment, alkali and alk. earth matrixes in river water and seawater matrixes could be completely removed. The resin can also successfully remove chloride and Se that can interfere with the direct detn. of Ge by ICP-MS. The applicability of the CCTS-DPA resin was further demonstrated for the collection/preconcn. of Ge in environmental H2O samples and its detn. by ICP-MS. The concns. of Ge in tap H2O, river water and seawater samples were found at 0.011-0.022 $mu$g L-1. [on SciFinder(R)] |
Bratescu, Maria Antoneta; Hieda, Junko; Umemura, Tomonari; Saito, Nagahiro; Takai, Osamu. Analysis of organic pollutant degradation in pulsed plasma by coherent anti-Stokes Raman spectroscopy. Journal Article In: Journal of Vacuum Science & Technology, A: Vacuum, Surfaces, and Films, vol. 29, no. 3, pp. 031302/1–031302/7, 2011, ISSN: 0734-2101. @article{Bratescu2011,
title = {Analysis of organic pollutant degradation in pulsed plasma by coherent anti-Stokes Raman spectroscopy.},
author = {Bratescu, Maria Antoneta and Hieda, Junko and Umemura, Tomonari and Saito, Nagahiro and Takai, Osamu.},
doi = {10.1116/1.3569035},
issn = {0734-2101},
year = {2011},
date = {2011-01-01},
journal = {Journal of Vacuum Science & Technology, A: Vacuum, Surfaces, and Films},
volume = {29},
number = {3},
pages = {031302/1--031302/7},
publisher = {American Institute of Physics},
abstract = {The degrdn. of p-benzoquinone (p-BQ) in H2O was studied by the coherent anti-Stokes Raman spectroscopy (CARS) method, in which the change of the anti-Stokes signal intensity corresponding to the vibrational transitions of the mol. is monitored during and after soln. plasma processing (SPP). In the beginning of SPP treatment, the CARS signal intensity of the ring vibrational mol. transitions at 1233 and 1660 cm-1 increases under the influence of the elec. field of the plasma, depending on the delay time between the plasma pulse and the laser firing pulse. At the same time, the plasma contributes to the degrdn. of p-BQ mols. by generating H and hydroxyl radicals, which decomp. p-BQ into different carboxylic acids. After SPP, the CARS signal intensity of the vibrational bands of p-BQ ceased and the degrdn. of p-BQ was confirmed by UV-visible absorption spectroscopy and liq. chromatog. anal. (c) 2011 American Institute of Physics. [on SciFinder(R)]},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
The degrdn. of p-benzoquinone (p-BQ) in H2O was studied by the coherent anti-Stokes Raman spectroscopy (CARS) method, in which the change of the anti-Stokes signal intensity corresponding to the vibrational transitions of the mol. is monitored during and after soln. plasma processing (SPP). In the beginning of SPP treatment, the CARS signal intensity of the ring vibrational mol. transitions at 1233 and 1660 cm-1 increases under the influence of the elec. field of the plasma, depending on the delay time between the plasma pulse and the laser firing pulse. At the same time, the plasma contributes to the degrdn. of p-BQ mols. by generating H and hydroxyl radicals, which decomp. p-BQ into different carboxylic acids. After SPP, the CARS signal intensity of the vibrational bands of p-BQ ceased and the degrdn. of p-BQ was confirmed by UV-visible absorption spectroscopy and liq. chromatog. anal. (c) 2011 American Institute of Physics. [on SciFinder(R)] |
Kumano, Naomi; Seki, Takahiro; Ishii, Masahiko; Nakamura, Hiroshi; Umemura, Tomonari; Takeoka, Yukikazu. Multicolor Polymer-Dispersed Liquid Crystal. Journal Article In: Advanced Materials (Weinheim, Germany), vol. 23, no. 7, pp. 884–888, 2011, ISSN: 0935-9648. @article{Kumano2011,
title = {Multicolor Polymer-Dispersed Liquid Crystal.},
author = {Kumano, Naomi and Seki, Takahiro and Ishii, Masahiko and Nakamura, Hiroshi and Umemura, Tomonari and Takeoka, Yukikazu.},
doi = {10.1002/adma.201003660},
issn = {0935-9648},
year = {2011},
date = {2011-01-01},
journal = {Advanced Materials (Weinheim, Germany)},
volume = {23},
number = {7},
pages = {884--888},
publisher = {Wiley-VCH Verlag GmbH & Co. KGaA},
abstract = {The authors demonstrate that a phase-sepd. porous N-methylmethylmethacrylamide-N,N'-methylene-bis-acrylamide polymer network filled with mixed liq. crystals of 5CB and 5PCH can exhibit changes in structural color covering the whole visible region and an opaque milky color upon temp. variation. In contrast to previously studied photonic band gap materials, this system is easy to prep. as a large-sized display due to its facile one-pot prepn. method and its mechanism of coloration. Because this composite film displays low- angle-dependent structural color and can act as a multicolor polymer dispersed liq. crystal, the authors believe that this system may be available for energy-saving multicolor displays. [on SciFinder(R)]},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
The authors demonstrate that a phase-sepd. porous N-methylmethylmethacrylamide-N,N'-methylene-bis-acrylamide polymer network filled with mixed liq. crystals of 5CB and 5PCH can exhibit changes in structural color covering the whole visible region and an opaque milky color upon temp. variation. In contrast to previously studied photonic band gap materials, this system is easy to prep. as a large-sized display due to its facile one-pot prepn. method and its mechanism of coloration. Because this composite film displays low- angle-dependent structural color and can act as a multicolor polymer dispersed liq. crystal, the authors believe that this system may be available for energy-saving multicolor displays. [on SciFinder(R)] |
2010 |
Imai, Takehito; Niwa, Masanao; Kawamura, Hideto; Umemura, Tomonari; Kimura, Masaru; Nakano, Takashi. The dyeing mechanism of oxidative hair color in white and black human hair. Journal Article In: Nippon Keshohin Gijutsusha Kaishi, vol. 44, no. 3, pp. 208–215, 2010, ISSN: 0387-5253. @article{Imai2010,
title = {The dyeing mechanism of oxidative hair color in white and black human hair.},
author = {Imai, Takehito and Niwa, Masanao and Kawamura, Hideto and Umemura, Tomonari and Kimura, Masaru and Nakano, Takashi.},
doi = {10.5107/sccj.44.208},
issn = {0387-5253},
year = {2010},
date = {2010-01-01},
journal = {Nippon Keshohin Gijutsusha Kaishi},
volume = {44},
number = {3},
pages = {208--215},
publisher = {Nippon Keshohin Gijutsushakai},
abstract = {The staining mechanism of oxidn. hair color on white hair and black hair in the same person was studied. The quant. anal. using ICP MS showed that the content of metals in the white hair was much less than that of the black one. This was due to low level of melanin granules in the white hair, one of the predominant structures contg. metals, that was obsd. with TEM and EDS-TEM. The results of this study also showed that the penetrating speed of oxidn. dyestuff monomers and of direct dyes into both the black hair and the white hair was the same under the condition without hydrogen peroxide, and the speed of direct dyes under the condition with or without hydrogen peroxide was also the same, and using oxidative dyestuffs the black hair had much higher staining efficacy in the presence of hydrogen peroxide than white hair. The fact that transition metals catalyze the oxidn. reaction of hydrogen peroxide has been known. Therefore, the difference in staining efficacy of oxidative dyestuffs in white hair and black hair in the presence of hydrogen peroxide in the staining solns. might be due to the difference of metal content that results from the difference in the no. of melanin granules in the hair. [on SciFinder(R)]},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
The staining mechanism of oxidn. hair color on white hair and black hair in the same person was studied. The quant. anal. using ICP MS showed that the content of metals in the white hair was much less than that of the black one. This was due to low level of melanin granules in the white hair, one of the predominant structures contg. metals, that was obsd. with TEM and EDS-TEM. The results of this study also showed that the penetrating speed of oxidn. dyestuff monomers and of direct dyes into both the black hair and the white hair was the same under the condition without hydrogen peroxide, and the speed of direct dyes under the condition with or without hydrogen peroxide was also the same, and using oxidative dyestuffs the black hair had much higher staining efficacy in the presence of hydrogen peroxide than white hair. The fact that transition metals catalyze the oxidn. reaction of hydrogen peroxide has been known. Therefore, the difference in staining efficacy of oxidative dyestuffs in white hair and black hair in the presence of hydrogen peroxide in the staining solns. might be due to the difference of metal content that results from the difference in the no. of melanin granules in the hair. [on SciFinder(R)] |
Koide, Hirotaka; Nagao, Yuki; Koumoto, Kunihito; Takasaki, Yuka; Umemura, Tomonari; Kato, Takeharu; Ikuhara, Yuichi; Ohta, Hiromichi. Electric field modulation of thermopower for transparent amorphous oxide thin film transistors. Journal Article In: Applied Physics Letters, vol. 97, no. 18, pp. 182105/1–182105/3, 2010, ISSN: 0003-6951. @article{Koide2010,
title = {Electric field modulation of thermopower for transparent amorphous oxide thin film transistors.},
author = {Koide, Hirotaka and Nagao, Yuki and Koumoto, Kunihito and Takasaki, Yuka and Umemura, Tomonari and Kato, Takeharu and Ikuhara, Yuichi and Ohta, Hiromichi.},
doi = {10.1063/1.3512870},
issn = {0003-6951},
year = {2010},
date = {2010-01-01},
journal = {Applied Physics Letters},
volume = {97},
number = {18},
pages = {182105/1--182105/3},
publisher = {American Institute of Physics},
abstract = {To clarify the electronic d. of states (DOS) around the conduction band bottom for state of the art transparent amorphous oxide semiconductors (TAOSs), InGaZnO4 and In2MgO4, we fabricated TAOS-based transparent thin film transistors (TTFTs) and measured their gate voltage dependence of thermopower (S). TAOS-based TTFTs exhibit an unusual S behavior. The |S|-value abruptly increases but then gradually decreases as Vg increases, clearly suggesting the antiparabolic shaped DOS is hybridized with the original parabolic shaped DOS around the conduction band bottom. (c) 2010 American Institute of Physics. [on SciFinder(R)]},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
To clarify the electronic d. of states (DOS) around the conduction band bottom for state of the art transparent amorphous oxide semiconductors (TAOSs), InGaZnO4 and In2MgO4, we fabricated TAOS-based transparent thin film transistors (TTFTs) and measured their gate voltage dependence of thermopower (S). TAOS-based TTFTs exhibit an unusual S behavior. The |S|-value abruptly increases but then gradually decreases as Vg increases, clearly suggesting the antiparabolic shaped DOS is hybridized with the original parabolic shaped DOS around the conduction band bottom. (c) 2010 American Institute of Physics. [on SciFinder(R)] |
Zhu, Yanbei; Itoh, Akihide; Umemura, Tomonari; Haraguchi, Hiroki; Inagaki, Kazumi; Chiba, Koichi. Determination of REEs in natural water by ICP-MS with the aid of an automatic column changing system. Journal Article In: Journal of Analytical Atomic Spectrometry, vol. 25, no. 8, pp. 1253–1258, 2010, ISSN: 0267-9477. @article{Zhu2010,
title = {Determination of REEs in natural water by ICP-MS with the aid of an automatic column changing system.},
author = {Zhu, Yanbei and Itoh, Akihide and Umemura, Tomonari and Haraguchi, Hiroki and Inagaki, Kazumi and Chiba, Koichi.},
doi = {10.1039/c003125a},
issn = {0267-9477},
year = {2010},
date = {2010-01-01},
journal = {Journal of Analytical Atomic Spectrometry},
volume = {25},
number = {8},
pages = {1253--1258},
publisher = {Royal Society of Chemistry},
abstract = {An automatic column changing system was developed for preconcn. and measurement of rare earth elements (REEs) in natural water samples, where syringe driven chelating columns (SDCCs) were applied to the hybrid (off-line operation and online operation) solid phase extn. of REEs. The sample loading was carried out off-line prior to the measurement. After that, the SDCCs were set into the column holder of the automatic column changing system and REEs were online eluted and measured by an inductively coupled plasma mass spectrometer (ICP-MS). The present automatic column changing system permitted continuously automatic measurement of 30 samples, while 3 min was enough for measuring one sample. The reproducibilities of REEs' signals obtained with 2 kinds of SDCCs showed that both of them are fit for the hybrid solid phase extn. method for preconcn. of REEs. The anal. detection limits (ADL) of REEs were from 0.013 pg/mL for Tm to 0.15 pg/mL for Ce when 10 mL water sample was loaded to each SDCC. The usefulness of this method was confirmed by analyzing NMIJ CRM 7201-a. REEs in Lake Baikal water samples from depth of 50, 100, 150, 200, 250 m were detd. The results showed that dissolved REEs in the sample of 50 m depth were significantly lower than other samples, while the total REEs in the sample of each depth were close to one another. The distribution of REEs in Lake Baikal water samples is discussed using shale normalized REEs distribution pattern. [on SciFinder(R)]},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
An automatic column changing system was developed for preconcn. and measurement of rare earth elements (REEs) in natural water samples, where syringe driven chelating columns (SDCCs) were applied to the hybrid (off-line operation and online operation) solid phase extn. of REEs. The sample loading was carried out off-line prior to the measurement. After that, the SDCCs were set into the column holder of the automatic column changing system and REEs were online eluted and measured by an inductively coupled plasma mass spectrometer (ICP-MS). The present automatic column changing system permitted continuously automatic measurement of 30 samples, while 3 min was enough for measuring one sample. The reproducibilities of REEs' signals obtained with 2 kinds of SDCCs showed that both of them are fit for the hybrid solid phase extn. method for preconcn. of REEs. The anal. detection limits (ADL) of REEs were from 0.013 pg/mL for Tm to 0.15 pg/mL for Ce when 10 mL water sample was loaded to each SDCC. The usefulness of this method was confirmed by analyzing NMIJ CRM 7201-a. REEs in Lake Baikal water samples from depth of 50, 100, 150, 200, 250 m were detd. The results showed that dissolved REEs in the sample of 50 m depth were significantly lower than other samples, while the total REEs in the sample of each depth were close to one another. The distribution of REEs in Lake Baikal water samples is discussed using shale normalized REEs distribution pattern. [on SciFinder(R)] |
Rahmi, Dwinna; Takasaki, Yuka; Zhu, Yanbei; Kobayashi, Hiroharu; Konagaya, Shigeji; Haraguchi, Hiroki; Umemura, Tomonari. Preparation of monolithic chelating adsorbent inside a syringe filter tip for solid phase microextraction of trace elements in natural water prior to their determination by ICP-MS. Journal Article In: Talanta, vol. 81, no. 4-5, pp. 1438–1445, 2010, ISSN: 0039-9140. @article{Rahmi2010,
title = {Preparation of monolithic chelating adsorbent inside a syringe filter tip for solid phase microextraction of trace elements in natural water prior to their determination by ICP-MS.},
author = {Rahmi, Dwinna and Takasaki, Yuka and Zhu, Yanbei and Kobayashi, Hiroharu and Konagaya, Shigeji and Haraguchi, Hiroki and Umemura, Tomonari.},
doi = {10.1016/j.talanta.2010.02.048},
issn = {0039-9140},
year = {2010},
date = {2010-01-01},
journal = {Talanta},
volume = {81},
number = {4-5},
pages = {1438--1445},
publisher = {Elsevier B.V.},
abstract = {A syringe-based sample pretreatment tool, named herein "tip-in chelating monolith", has been developed for simple and facile solid phase microextn. (SPME) of trace elements in natural waters. The tip-in chelating monolith was directly prepd. within the confines of a com. available syringe filter tip by a two-step process: (1) in situ polymn. of a monomer soln. consisting of 22.5% glycidyl methacrylate (GMA), 7.5% ethylene glycol dimethacrylate (EDMA), 35% 1-propanol, 28% 1,4-butanediol, and 7% water and (2) its subsequent modification with 1 mol L-1 of iminodiacetate soln. (adjusted to pH 10) via ring-opening reaction of epoxide. The adsorption properties of the tip-in chelating monolith thus obtained were evaluated through an adsorption/desorption expt., where the effects of sample soln. pH and eluent on the SPME of trace metals and metalloids were systematically examd. Consequently, when sample soln. pH was adjusted to 5.0 and 0.9 mL of 2 mol L-1 nitric acid was used as an eluent, good recoveries of more than 80% were obtained for 27 elements in a single-step extn. The proposed SPME method was validated through the anal. of two river water certified ref. materials (CRMs: JSAC 0301-1 and NMIJ 7201-a). After 50-fold preconcn. (from 50 mL of the original river water sample to 1.0 mL of final anal. soln.), 22 trace elements including Ti, Fe, Co, Ni, Cu, Ga, Cd, Sn and REEs were quant. detd. by inductively coupled plasma mass spectrometry (ICP-MS). The anal. detection limits were in the range from 0.000003 $mu$g L-1 for Ho to 0.18 $mu$g L-1 for Fe. Good agreement of the obsd. values with the certified or ref. values indicates that the proposed SPME using the tip-in chelating monolith is practically applicable. [on SciFinder(R)]},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
A syringe-based sample pretreatment tool, named herein "tip-in chelating monolith", has been developed for simple and facile solid phase microextn. (SPME) of trace elements in natural waters. The tip-in chelating monolith was directly prepd. within the confines of a com. available syringe filter tip by a two-step process: (1) in situ polymn. of a monomer soln. consisting of 22.5% glycidyl methacrylate (GMA), 7.5% ethylene glycol dimethacrylate (EDMA), 35% 1-propanol, 28% 1,4-butanediol, and 7% water and (2) its subsequent modification with 1 mol L-1 of iminodiacetate soln. (adjusted to pH 10) via ring-opening reaction of epoxide. The adsorption properties of the tip-in chelating monolith thus obtained were evaluated through an adsorption/desorption expt., where the effects of sample soln. pH and eluent on the SPME of trace metals and metalloids were systematically examd. Consequently, when sample soln. pH was adjusted to 5.0 and 0.9 mL of 2 mol L-1 nitric acid was used as an eluent, good recoveries of more than 80% were obtained for 27 elements in a single-step extn. The proposed SPME method was validated through the anal. of two river water certified ref. materials (CRMs: JSAC 0301-1 and NMIJ 7201-a). After 50-fold preconcn. (from 50 mL of the original river water sample to 1.0 mL of final anal. soln.), 22 trace elements including Ti, Fe, Co, Ni, Cu, Ga, Cd, Sn and REEs were quant. detd. by inductively coupled plasma mass spectrometry (ICP-MS). The anal. detection limits were in the range from 0.000003 $mu$g L-1 for Ho to 0.18 $mu$g L-1 for Fe. Good agreement of the obsd. values with the certified or ref. values indicates that the proposed SPME using the tip-in chelating monolith is practically applicable. [on SciFinder(R)] |
Fujiwara, Kitao; Osako, Yuta; Sasaki, Takana; Kumata, Hidetoshi; Aoki, Motohide; Kawashima, Norio. Construction of photo-decomposer for organic compounds in natural water and evaluation of its performance by chemiluminescence. Journal Article In: Bunseki Kagaku, vol. 59, no. 11, pp. 1021–1028, 2010, ISSN: 0525-1931. @article{Fujiwara2010,
title = {Construction of photo-decomposer for organic compounds in natural water and evaluation of its performance by chemiluminescence.},
author = {Kitao Fujiwara and Yuta Osako and Takana Sasaki and Hidetoshi Kumata and Motohide Aoki and Norio. Kawashima},
doi = {10.2116/bunsekikagaku.59.1021},
issn = {0525-1931},
year = {2010},
date = {2010-01-01},
journal = {Bunseki Kagaku},
volume = {59},
number = {11},
pages = {1021--1028},
publisher = {Nippon Bunseki Kagakkai},
abstract = {COD is one of the most popular methods for evaluating org. pollutants. In the present paper, a chemiluminescence detection method for measuring the concn. of permanganate ion after reacting with org. compds. is described; the chemiluminescence occurs based on the direct reaction between permanganate and luminol. In order to use this system, a buffer soln., the concns. of permanganate and luminol were inspected. Fifty $mu$M of MnO4 was reacted with the sample, and then the chemiluminescence was detected with a mixt. soln. (250 mL of 1.5 mM luminol, 250 mL of 0.01 M 1,10-phenanthroline, and 500 mL of 1 M ammonium sulfate at pH 9.6, adjusted with 25% ammonium soln.). Also, a method for reducing the COD was proposed: where the sample soln. flows a 100 m length PFA (perfluoroalkoxy-fluororesin) microtube (i.d. = 0.2 mm and o.d. = 0.4 mm). The PFA tube was wound around the outside of a quartz tube (o.d. = 30 mm},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
COD is one of the most popular methods for evaluating org. pollutants. In the present paper, a chemiluminescence detection method for measuring the concn. of permanganate ion after reacting with org. compds. is described; the chemiluminescence occurs based on the direct reaction between permanganate and luminol. In order to use this system, a buffer soln., the concns. of permanganate and luminol were inspected. Fifty $mu$M of MnO4 was reacted with the sample, and then the chemiluminescence was detected with a mixt. soln. (250 mL of 1.5 mM luminol, 250 mL of 0.01 M 1,10-phenanthroline, and 500 mL of 1 M ammonium sulfate at pH 9.6, adjusted with 25% ammonium soln.). Also, a method for reducing the COD was proposed: where the sample soln. flows a 100 m length PFA (perfluoroalkoxy-fluororesin) microtube (i.d. = 0.2 mm and o.d. = 0.4 mm). The PFA tube was wound around the outside of a quartz tube (o.d. = 30 mm |
2009 |
Umemura, Tomonari; Kobayshi, Hiroharu. Development of comprehensive two-dimensional HPLC system for protein analysis. Journal Article In: Chromatography, vol. 30, no. Suppl. 1, pp. 43–44, 2009, ISSN: 1342-8284. @article{Umemura2009,
title = {Development of comprehensive two-dimensional HPLC system for protein analysis.},
author = {Umemura, Tomonari and Kobayshi, Hiroharu.},
issn = {1342-8284},
year = {2009},
date = {2009-01-01},
journal = {Chromatography},
volume = {30},
number = {Suppl. 1},
pages = {43--44},
publisher = {Kuromatogurafi Kagakkai},
abstract = {A simple and straightforward comprehensive two-dimensional liq. chromatog. system was constructed by making full use of monolithic column technol. The system consists of strong cation-exchange (SCX) chromatog. in the first dimension and reversed-phase (RP) liq. chromatog. in the second dimension. The SCX and RP columns were custom-made in our lab. by in situ copolymn. of functional monomer and crosslinker. The two LC systems were coupled by a ten-port two position valve equipped with two storage loops. The resolving power of this system was demonstrated with a two-dimensional chromatogram of the peptides obtained from a tryptic digest of bovine serum albumin (BSA). Following the two-dimensional chromatog. sepn., the peptide fragments were directly detected by both UV-absorbance (214 nm) and on line ESI-MS. [on SciFinder(R)]},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
A simple and straightforward comprehensive two-dimensional liq. chromatog. system was constructed by making full use of monolithic column technol. The system consists of strong cation-exchange (SCX) chromatog. in the first dimension and reversed-phase (RP) liq. chromatog. in the second dimension. The SCX and RP columns were custom-made in our lab. by in situ copolymn. of functional monomer and crosslinker. The two LC systems were coupled by a ten-port two position valve equipped with two storage loops. The resolving power of this system was demonstrated with a two-dimensional chromatogram of the peptides obtained from a tryptic digest of bovine serum albumin (BSA). Following the two-dimensional chromatog. sepn., the peptide fragments were directly detected by both UV-absorbance (214 nm) and on line ESI-MS. [on SciFinder(R)] |
Hotta, Hiroki; Mori, Takayuki; Takahashi, Akira; Kogure, Yuta; Johno, Keita; Umemura, Tomonari; Tsunoda, Kin-ichi. Quantification of Trace Elements in Natural Samples by Electrospray Ionization Mass Spectrometry with a Size-Exclusion Column Based on the Formation of Metal-Aminopolycarboxylate Complexes. Journal Article In: Analytical Chemistry (Washington, DC, United States), vol. 81, no. 15, pp. 6357–6363, 2009, ISSN: 0003-2700. @article{Hotta2009,
title = {Quantification of Trace Elements in Natural Samples by Electrospray Ionization Mass Spectrometry with a Size-Exclusion Column Based on the Formation of Metal-Aminopolycarboxylate Complexes.},
author = {Hotta, Hiroki and Mori, Takayuki and Takahashi, Akira and Kogure, Yuta and Johno, Keita and Umemura, Tomonari and Tsunoda, Kin-ichi.},
doi = {10.1021/ac9006842},
issn = {0003-2700},
year = {2009},
date = {2009-01-01},
journal = {Analytical Chemistry (Washington, DC, United States)},
volume = {81},
number = {15},
pages = {6357--6363},
publisher = {American Chemical Society},
abstract = {Metal ions were detd. by ESI-MS in the neg. ion mode as monovalent neg. ions of their aminopolycarboxylic acid (APC) complexes, e.g., [Al(cydta)]-, [Pb(Hcydta)]-, where excess amts. of the APC agents were added to sample solns. Among several APCs studied, the authors chose trans-1,2-diaminocyclohexane-N,N,N',N'-tetraacetic acid (CyDTA) as the best chelating agent because of higher stabilities and higher sensitivities of the complexes. The ionization efficiency of these metal complexes was strongly affected by the presence of matrix salts, e.g., NaCl, KNO3, and etc. Thus, a size exclusion column (Sephadex G-10) was used for the online sepn. of the metal-APC complexes from other matrix salts. This method was successfully applied to the quant. analyses for total amts. of Al, Ni, Cu, Zn, and Pb in the biol. certified ref. materials, olive leaves (BCR-062) and plankton (BCR-414). The detection limits of the present methods for these elements were several to several ten nanomolar levels. Also, this approach was extended to det. ultratraces of fluoride based on the formation of the ternary complex of Al, fluoride and nitrilotriacetic acid (NTA), i.e., [AlF(nta)]-. Its detection limit was 10 nM and was 2 orders of magnitude better than that of a F- ion selective electrode method. This method was applied to det. fluoride in tap H2O, river water, and green tea samples. [on SciFinder(R)]},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Metal ions were detd. by ESI-MS in the neg. ion mode as monovalent neg. ions of their aminopolycarboxylic acid (APC) complexes, e.g., [Al(cydta)]-, [Pb(Hcydta)]-, where excess amts. of the APC agents were added to sample solns. Among several APCs studied, the authors chose trans-1,2-diaminocyclohexane-N,N,N',N'-tetraacetic acid (CyDTA) as the best chelating agent because of higher stabilities and higher sensitivities of the complexes. The ionization efficiency of these metal complexes was strongly affected by the presence of matrix salts, e.g., NaCl, KNO3, and etc. Thus, a size exclusion column (Sephadex G-10) was used for the online sepn. of the metal-APC complexes from other matrix salts. This method was successfully applied to the quant. analyses for total amts. of Al, Ni, Cu, Zn, and Pb in the biol. certified ref. materials, olive leaves (BCR-062) and plankton (BCR-414). The detection limits of the present methods for these elements were several to several ten nanomolar levels. Also, this approach was extended to det. ultratraces of fluoride based on the formation of the ternary complex of Al, fluoride and nitrilotriacetic acid (NTA), i.e., [AlF(nta)]-. Its detection limit was 10 nM and was 2 orders of magnitude better than that of a F- ion selective electrode method. This method was applied to det. fluoride in tap H2O, river water, and green tea samples. [on SciFinder(R)] |
Zhu, Yanbei; Umemura, Tomonari; Haraguchi, Hiroki; Inagaki, Kazumi; Chiba, Koichi. Determination of REEs in seawater by ICP-MS after on-line preconcentration using a syringe-driven chelating column. Journal Article In: Talanta, vol. 78, no. 3, pp. 891–895, 2009, ISSN: 0039-9140. @article{Zhu2009,
title = {Determination of REEs in seawater by ICP-MS after on-line preconcentration using a syringe-driven chelating column.},
author = {Zhu, Yanbei and Umemura, Tomonari and Haraguchi, Hiroki and Inagaki, Kazumi and Chiba, Koichi.},
doi = {10.1016/j.talanta.2008.12.072},
issn = {0039-9140},
year = {2009},
date = {2009-01-01},
journal = {Talanta},
volume = {78},
number = {3},
pages = {891--895},
publisher = {Elsevier B.V.},
abstract = {A syringe-driven chelating column (SDCC) was applied to develop an online preconcn./inductively coupled plasma mass spectrometry (ICP-MS) method for preconcn. and detn. of rare earth elements (REEs) in seawater samples. The present online preconcn. system consists of only one pump, two valves, an SDCC, an ICP-MS, several connectors, and Teflon tubes. Optimizations of adsorption pH condition, sample loading flow rate, and integration range were carried out to achieve optimum measurement conditions for REEs in seawater sample. Six minutes was enough for a preconcn. and measurement cycle using 10 mL of seawater sample, where the detection limits for different REEs were in the range of 0.005 pg mL-1 to 0.09 pg mL-1. Anal. results of REEs in a seawater certified ref. material (CRM), NASS-5, confirmed the usefulness of the present method. Also, concns. of REEs in Nikkawa Beach coastal seawater were detd. and discussed with shale normalized REE distribution pattern. [on SciFinder(R)]},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
A syringe-driven chelating column (SDCC) was applied to develop an online preconcn./inductively coupled plasma mass spectrometry (ICP-MS) method for preconcn. and detn. of rare earth elements (REEs) in seawater samples. The present online preconcn. system consists of only one pump, two valves, an SDCC, an ICP-MS, several connectors, and Teflon tubes. Optimizations of adsorption pH condition, sample loading flow rate, and integration range were carried out to achieve optimum measurement conditions for REEs in seawater sample. Six minutes was enough for a preconcn. and measurement cycle using 10 mL of seawater sample, where the detection limits for different REEs were in the range of 0.005 pg mL-1 to 0.09 pg mL-1. Anal. results of REEs in a seawater certified ref. material (CRM), NASS-5, confirmed the usefulness of the present method. Also, concns. of REEs in Nikkawa Beach coastal seawater were detd. and discussed with shale normalized REE distribution pattern. [on SciFinder(R)] |
2008 |
Fujiwara, Kitao; Suematsu, Hitoshi; Kiyomiya, Emiko; Aoki, Motohide; Sato, Mamiko; Moritoki, Nobuko Size-dependent toxicity of silica nano-particles to Chlorella kessleri. Journal Article In: Journal of environmental science and health. Part A, Toxic/hazardous substances & environmental engineering, vol. 43, no. 10, pp. 1167–73, 2008, ISSN: 1093-4529. @article{Fujiwara2008b,
title = {Size-dependent toxicity of silica nano-particles to Chlorella kessleri.},
author = {Kitao Fujiwara and Hitoshi Suematsu and Emiko Kiyomiya and Motohide Aoki and Mamiko Sato and Nobuko Moritoki},
url = {http://www.ncbi.nlm.nih.gov/pubmed/18584432},
doi = {10.1080/10934520802171675},
issn = {1093-4529},
year = {2008},
date = {2008-08-01},
journal = {Journal of environmental science and health. Part A, Toxic/hazardous substances & environmental engineering},
volume = {43},
number = {10},
pages = {1167--73},
abstract = {SiO(2) nano-particles were found to exhibit size-dependent toxicity toward the alga, Chlorella kessleri. Small SiO(2) nano-particles exhibit stronger toxicity: 50% inhibitory concentrations (IC(50)) value for 5 nm = 0.8 +/- 0.6%, 26 nm = 7.1 +/- 2.8%, and 78 nm = 9.1 +/- 4.7%. Enlargement of the cell body was observed by flow cytometry, which is due to the presence of structures that obstructed cell division. Optical and transmission microscopes were used to observe coagulated cells with incomplete division. Although the physiological effect of SiO(2) nano-particles was not clear, SiO(2) nano-particles are toxic, at least for algae in aquatic media. Under the transmission electron microscope, several amorphous structures appeared in the cells that were exposed to 5-nm silica nano-particles.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
SiO(2) nano-particles were found to exhibit size-dependent toxicity toward the alga, Chlorella kessleri. Small SiO(2) nano-particles exhibit stronger toxicity: 50% inhibitory concentrations (IC(50)) value for 5 nm = 0.8 +/- 0.6%, 26 nm = 7.1 +/- 2.8%, and 78 nm = 9.1 +/- 4.7%. Enlargement of the cell body was observed by flow cytometry, which is due to the presence of structures that obstructed cell division. Optical and transmission microscopes were used to observe coagulated cells with incomplete division. Although the physiological effect of SiO(2) nano-particles was not clear, SiO(2) nano-particles are toxic, at least for algae in aquatic media. Under the transmission electron microscope, several amorphous structures appeared in the cells that were exposed to 5-nm silica nano-particles. |
Umemura, Tomonari; Kojima, Norihisa; Ueki, Yuji Development of high-throughput analysis system using highly-functional organic polymer monoliths Journal Article In: BUNSEKI KAGAKU, vol. 57, no. 7, pp. 517–529, 2008, ISSN: 0525-1931. @article{梅村知也:2008-07-05,
title = {Development of high-throughput analysis system using highly-functional organic polymer monoliths},
author = {Umemura, Tomonari and Kojima, Norihisa and Ueki, Yuji},
url = {http://ci.nii.ac.jp/naid/110006825844/},
doi = {10.2116/bunsekikagaku.57.517},
issn = {0525-1931},
year = {2008},
date = {2008-07-01},
journal = {BUNSEKI KAGAKU},
volume = {57},
number = {7},
pages = {517--529},
publisher = {社団法人日本分析化学会},
abstract = {三次元的に連通した空孔を有する多孔質体(モノリス)は,従来の粒子充填型の担体と比較して,流体透過性が高く,また,物質移動効率に優れていることから,高速かつ高性能な分離・反応を低圧損で実現できる基盤材料・デバイスとして注目を集めている.著者らは,有機ポリマー製のモノリスカラムの高性能化と高機能化に取り組み,分離,精製,濃縮,反応等の化学操作を迅速かつ高効率に行えるデバイスの作製を検討してきた.更に,これらのデバイスを組み合わせて,低コストで省力的なマイクロ化学分析システムの開発を進めている.本稿では,著者らが最近取り組んでいる内径1mmのセミミクロサイズのモノリスカラムの研究成果を中心にその有用性を紹介する.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
三次元的に連通した空孔を有する多孔質体(モノリス)は,従来の粒子充填型の担体と比較して,流体透過性が高く,また,物質移動効率に優れていることから,高速かつ高性能な分離・反応を低圧損で実現できる基盤材料・デバイスとして注目を集めている.著者らは,有機ポリマー製のモノリスカラムの高性能化と高機能化に取り組み,分離,精製,濃縮,反応等の化学操作を迅速かつ高効率に行えるデバイスの作製を検討してきた.更に,これらのデバイスを組み合わせて,低コストで省力的なマイクロ化学分析システムの開発を進めている.本稿では,著者らが最近取り組んでいる内径1mmのセミミクロサイズのモノリスカラムの研究成果を中心にその有用性を紹介する. |
Imai, Takehito; Niwa, Masanao; Hasegawa, Takuya; Kawamura, Hideto; Umemura, Tomonari; Kimura, Masaru; Nakano, Takashi; Haraguchi, Hiroki. The reaction of oxidative hair dyes in cuticle layers. Journal Article In: Nippon Keshohin Gijutsusha Kaishi, vol. 42, no. 4, pp. 305–312, 2008, ISSN: 0387-5253. @article{Imai2008,
title = {The reaction of oxidative hair dyes in cuticle layers.},
author = {Imai, Takehito and Niwa, Masanao and Hasegawa, Takuya and Kawamura, Hideto and Umemura, Tomonari and Kimura, Masaru and Nakano, Takashi and Haraguchi, Hiroki.},
doi = {10.5107/sccj.42.305},
issn = {0387-5253},
year = {2008},
date = {2008-01-01},
journal = {Nippon Keshohin Gijutsusha Kaishi},
volume = {42},
number = {4},
pages = {305--312},
publisher = {Nippon Keshohin Gijutsushakai},
abstract = {The mechanism of oxidative hair dyes (permanent hair color) in cuticle layers of human hair was studied. In general, it is considered that the oxidative hair dye deposits monomer into the cortex, and is polymd. with coloring in there. It was confirmed that not only cortex but also cuticle layers were dyed with the permanent hair color, through observation with the thin cross-section of the dyed hair. There were exogenous metals in the cuticle layers from tap water, etc., and the transition metals increased the dyeing and decreased the bleaching. It was thought that the activity of oxidn. reaction with hydrogen peroxide was increased in the cuticle layers, and permeability to the cortex was decreased. Furthermore, TEM findings suggested that the oxidn. hair dyes mainly reacted in the $beta$-layer/$delta$-layer interface in the cuticle layers, unevenly distributing the metals in the $beta$-layer of cuticular CMC. [on SciFinder(R)]},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
The mechanism of oxidative hair dyes (permanent hair color) in cuticle layers of human hair was studied. In general, it is considered that the oxidative hair dye deposits monomer into the cortex, and is polymd. with coloring in there. It was confirmed that not only cortex but also cuticle layers were dyed with the permanent hair color, through observation with the thin cross-section of the dyed hair. There were exogenous metals in the cuticle layers from tap water, etc., and the transition metals increased the dyeing and decreased the bleaching. It was thought that the activity of oxidn. reaction with hydrogen peroxide was increased in the cuticle layers, and permeability to the cortex was decreased. Furthermore, TEM findings suggested that the oxidn. hair dyes mainly reacted in the $beta$-layer/$delta$-layer interface in the cuticle layers, unevenly distributing the metals in the $beta$-layer of cuticular CMC. [on SciFinder(R)] |
Haraguchi, Hiroki; Ishii, Atsushi; Hasegawa, Takuya; Matsuura, Hirotaka; Umemura, Tomonari. Metallomics study on all-elements analysis of salmon egg cells and fractionation analysis of metals in cell cytoplasm. Journal Article In: Pure and Applied Chemistry, vol. 80, no. 12, pp. 2595–2608, 2008, ISSN: 0033-4545. @article{Haraguchi2008,
title = {Metallomics study on all-elements analysis of salmon egg cells and fractionation analysis of metals in cell cytoplasm.},
author = {Haraguchi, Hiroki and Ishii, Atsushi and Hasegawa, Takuya and Matsuura, Hirotaka and Umemura, Tomonari.},
doi = {10.1351/pac200880122595},
issn = {0033-4545},
year = {2008},
date = {2008-01-01},
journal = {Pure and Applied Chemistry},
volume = {80},
number = {12},
pages = {2595--2608},
publisher = {International Union of Pure and Applied Chemistry},
abstract = {Salmon egg cells were the subject of investigation for all-elements anal. in a single biol. cell, where the elements in egg cells were simultaneously detd. by inductively coupled plasma at. emission spectrometry (ICP-AES) and inductively coupled plasma mass spectrometry (ICP-MS) after microwave-assisted acid digestion. As a result, 74 elements among 78 stable isotope elements were detd. or detected, although H, C, N, and O were detd. sep. by conventional CHN elemental anal. In addn., the survey of protein-binding metallic elements as well as metalloid elements in salmon egg cell cytoplasm was performed by the fractionation anal. with a hyphenated system of high-performance liq. chromatog. (HPLC)/ICP-MS using a 3-[(3-cholamidopropyl)-di-methylammonio]-1-propane sulfonate (CHAPS)-coated octadecylsilyl silica (ODS) column and a size exclusion chromatog. (SEC) column. [on SciFinder(R)]},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Salmon egg cells were the subject of investigation for all-elements anal. in a single biol. cell, where the elements in egg cells were simultaneously detd. by inductively coupled plasma at. emission spectrometry (ICP-AES) and inductively coupled plasma mass spectrometry (ICP-MS) after microwave-assisted acid digestion. As a result, 74 elements among 78 stable isotope elements were detd. or detected, although H, C, N, and O were detd. sep. by conventional CHN elemental anal. In addn., the survey of protein-binding metallic elements as well as metalloid elements in salmon egg cell cytoplasm was performed by the fractionation anal. with a hyphenated system of high-performance liq. chromatog. (HPLC)/ICP-MS using a 3-[(3-cholamidopropyl)-di-methylammonio]-1-propane sulfonate (CHAPS)-coated octadecylsilyl silica (ODS) column and a size exclusion chromatog. (SEC) column. [on SciFinder(R)] |
Rahmi, Dwinna; Zhu, Yanbei; Umemura, Tomonari; Haraguchi, Hiroki; Itoh, Akihide; Chiba, Koichi. Determination of 56 elements in lake Baikal water by high-resolution ICP-MS with the aid of a tandem preconcentration method. Journal Article In: Analytical Sciences, vol. 24, no. 11, pp. 1513–1517, 2008, ISSN: 0910-6340. @article{Rahmi2008,
title = {Determination of 56 elements in lake Baikal water by high-resolution ICP-MS with the aid of a tandem preconcentration method.},
author = {Rahmi, Dwinna and Zhu, Yanbei and Umemura, Tomonari and Haraguchi, Hiroki and Itoh, Akihide and Chiba, Koichi.},
doi = {10.2116/analsci.24.1513},
issn = {0910-6340},
year = {2008},
date = {2008-01-01},
journal = {Analytical Sciences},
volume = {24},
number = {11},
pages = {1513--1517},
publisher = {Japan Society for Analytical Chemistry},
abstract = {A tandem preconcn. method integrating chelating resin adsorption and La copptn. was applied to the anal. of Lake Baikal water by high-resoln. ICP-MS. As a result, 56 elements were detd. in Lake Baikal water: Ca, Na, Mg, K, Si, Sr, B, Li, Ba, P, Fe, Al, Mo, Zn, Mn, Rb, U, As, V, Cu, Pb, W, Y, Cs, Se, Cr, Ni, Ti, Sb, Zr, Sn, Co, Cd, Rh, Te, Hf, Nb, Ru, Ga, Sc, Th, Bi, and all-rare earth elements (all-REEs), except for Pm. The concns. of these elements covered a range of 9 orders of magnitude, from ∼17 $mu$g/mL of Ca to <50 fg/mL of Tm. The elemental concns. in Lake Baikal water were compared with ref. data. [on SciFinder(R)]},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
A tandem preconcn. method integrating chelating resin adsorption and La copptn. was applied to the anal. of Lake Baikal water by high-resoln. ICP-MS. As a result, 56 elements were detd. in Lake Baikal water: Ca, Na, Mg, K, Si, Sr, B, Li, Ba, P, Fe, Al, Mo, Zn, Mn, Rb, U, As, V, Cu, Pb, W, Y, Cs, Se, Cr, Ni, Ti, Sb, Zr, Sn, Co, Cd, Rh, Te, Hf, Nb, Ru, Ga, Sc, Th, Bi, and all-rare earth elements (all-REEs), except for Pm. The concns. of these elements covered a range of 9 orders of magnitude, from ∼17 $mu$g/mL of Ca to <50 fg/mL of Tm. The elemental concns. in Lake Baikal water were compared with ref. data. [on SciFinder(R)] |
Rahmi, Dwinna; Zhu, Yanbei; Fujimori, Eiji; Hasegawa, Takuya; Umemura, Tomonari; Konagaya, Shigeji; Haraguchi, Hiroki. An in-syringe La-coprecipitation method for the preconcentration of oxo-anion forming elements in seawater prior to an ICP-MS measurement. Journal Article In: Analytical Sciences, vol. 24, no. 9, pp. 1189–1192, 2008, ISSN: 0910-6340. @article{Rahmi2008a,
title = {An in-syringe La-coprecipitation method for the preconcentration of oxo-anion forming elements in seawater prior to an ICP-MS measurement.},
author = {Rahmi, Dwinna and Zhu, Yanbei and Fujimori, Eiji and Hasegawa, Takuya and Umemura, Tomonari and Konagaya, Shigeji and Haraguchi, Hiroki.},
doi = {10.2116/analsci.24.1189},
issn = {0910-6340},
year = {2008},
date = {2008-01-01},
journal = {Analytical Sciences},
volume = {24},
number = {9},
pages = {1189--1192},
publisher = {Japan Society for Analytical Chemistry},
abstract = {A La copptn. method with low sample consumption was explored for the preconcn. of oxo-anion forming elements prior to a measurement by inductively coupled plasma mass spectrometry (ICP-MS). The preconcn. procedure was composed of 2 main steps: (1) the formation of a coppt. with the lowest possible La and (2) the redissoln. of target analytes with minimal use of nitric acid, and the elimination of high concn. La from the anal. sample. Each step was performed in a 25 mL-vol. syringe to reduce the sample consumption and to avoid contamination from the exptl. environment. Various parameters, such as the concn. and vol. of La added into the sample soln., the pptn. pH, the aging time, and the vol. of HNO3 were optimized to obtain good recoveries and high detection sensitivities for V, As, Sb, and W, which could be hardly recovered by solid-phase extn. using a chelating resin. The obtained method was evaluated through the anal. of seawater ref. materials (CASS-4 and NASS-5). The recoveries exceeded 80%, and the obsd. values were in good agreement with the certified values. [on SciFinder(R)]},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
A La copptn. method with low sample consumption was explored for the preconcn. of oxo-anion forming elements prior to a measurement by inductively coupled plasma mass spectrometry (ICP-MS). The preconcn. procedure was composed of 2 main steps: (1) the formation of a coppt. with the lowest possible La and (2) the redissoln. of target analytes with minimal use of nitric acid, and the elimination of high concn. La from the anal. sample. Each step was performed in a 25 mL-vol. syringe to reduce the sample consumption and to avoid contamination from the exptl. environment. Various parameters, such as the concn. and vol. of La added into the sample soln., the pptn. pH, the aging time, and the vol. of HNO3 were optimized to obtain good recoveries and high detection sensitivities for V, As, Sb, and W, which could be hardly recovered by solid-phase extn. using a chelating resin. The obtained method was evaluated through the anal. of seawater ref. materials (CASS-4 and NASS-5). The recoveries exceeded 80%, and the obsd. values were in good agreement with the certified values. [on SciFinder(R)] |
Hotta, Hiroki; Wang, Qiang; Fukuda, Mioko; Aizawa, Shoichi; Umemura, Tomonari; Sekizawa, Kazutoshi; Tsunoda, Kin-ichi. Identification of aluminum species in an aluminum-accumulating plant, hydrangea (Hydrangea macrophylla), by electrospray ionization mass spectrometry. Journal Article In: Analytical Sciences, vol. 24, no. 6, pp. 795–798, 2008, ISSN: 0910-6340. @article{Hotta2008,
title = {Identification of aluminum species in an aluminum-accumulating plant, hydrangea (Hydrangea macrophylla), by electrospray ionization mass spectrometry.},
author = {Hotta, Hiroki and Wang, Qiang and Fukuda, Mioko and Aizawa, Shoichi and Umemura, Tomonari and Sekizawa, Kazutoshi and Tsunoda, Kin-ichi.},
doi = {10.2116/analsci.24.795},
issn = {0910-6340},
year = {2008},
date = {2008-01-01},
journal = {Analytical Sciences},
volume = {24},
number = {6},
pages = {795--798},
publisher = {Japan Society for Analytical Chemistry},
abstract = {The use of electrospray ionization mass spectrometry (ESI-MS) in neg. ion mode was investigated as a direct probe for identifying Al species in Al-accumulating hydrangea (Hydrangea macrophylla) samples. Cell sap solns. of hydrangea leaves were purified using Sephadex G-10 liq. chromatog. and each fraction was analyzed using ESI-MS and ESI-MS/MS to identify Al species. In hydrangea leaves, a 1:1 Al-citrate complex was found as [AlH-1cit]- (m/z 215), where H3cit denotes citric acid. This result is consistent with that of Ma et al. (1997) who used 27Al-NMR. [on SciFinder(R)]},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
The use of electrospray ionization mass spectrometry (ESI-MS) in neg. ion mode was investigated as a direct probe for identifying Al species in Al-accumulating hydrangea (Hydrangea macrophylla) samples. Cell sap solns. of hydrangea leaves were purified using Sephadex G-10 liq. chromatog. and each fraction was analyzed using ESI-MS and ESI-MS/MS to identify Al species. In hydrangea leaves, a 1:1 Al-citrate complex was found as [AlH-1cit]- (m/z 215), where H3cit denotes citric acid. This result is consistent with that of Ma et al. (1997) who used 27Al-NMR. [on SciFinder(R)] |
Fujiwara, Kitao; Hirokawa, Shun; Aoki, Motohide. Comparison of fluorescence correlation spectrometry with the ordinary fluorescence optical configuration with flow cytometry as a tool for micrometer-level size determination. Journal Article In: Analytical Sciences, vol. 24, no. 12, pp. 1623–1627, 2008, ISSN: 0910-6340. @article{Fujiwara2008bb,
title = {Comparison of fluorescence correlation spectrometry with the ordinary fluorescence optical configuration with flow cytometry as a tool for micrometer-level size determination.},
author = {Kitao Fujiwara and Shun Hirokawa and Motohide. Aoki},
doi = {10.2116/analsci.24.1623},
issn = {0910-6340},
year = {2008},
date = {2008-01-01},
journal = {Analytical Sciences},
volume = {24},
number = {12},
pages = {1623--1627},
publisher = {Japan Society for Analytical Chemistry},
abstract = {As a tool for micrometer-level size detn., fluorescence correlation spectroscopy (FCS), performed based on our previous report, was compared to flow cytometry (FCM). For this purpose, std. fluorescent beads were subjected to both methods. And hence, it was found that our FCS is a useful method with satisfactory precision for size detns. of individual particles at micrometer size levels, while providing the av. size for a mixt. of two kinds of particles with different sizes. [on SciFinder(R)]},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
As a tool for micrometer-level size detn., fluorescence correlation spectroscopy (FCS), performed based on our previous report, was compared to flow cytometry (FCM). For this purpose, std. fluorescent beads were subjected to both methods. And hence, it was found that our FCS is a useful method with satisfactory precision for size detns. of individual particles at micrometer size levels, while providing the av. size for a mixt. of two kinds of particles with different sizes. [on SciFinder(R)] |
Fujiwara, Kitao; Matsumoto, Yoshiko; Kawakami, Hayato; Aoki, Motohide; Tuzuki, Mikio Evaluation of metal toxicity in Chlorella kessleri from the perspective of the periodic table Journal Article In: Bulletin of the Chemical Society of Japan, vol. 81, no. 4, pp. 478–488, 2008. @article{Fujiwara2008a,
title = {Evaluation of metal toxicity in Chlorella kessleri from the perspective of the periodic table},
author = {Kitao Fujiwara and Yoshiko Matsumoto and Hayato Kawakami and Motohide Aoki and Mikio Tuzuki},
doi = {10.1246/bcsj.81.478},
year = {2008},
date = {2008-01-01},
journal = {Bulletin of the Chemical Society of Japan},
volume = {81},
number = {4},
pages = {478--488},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
|
2007 |
Rahmi, Dwinna; Zhu, Yanbei; Fujimori, Eiji; Umemura, Tomonari; Haraguchi, Hiroki. Multielement determination of trace metals in seawater by ICP-MS with aid of down-sized chelating resin-packed minicolumn for preconcentration. Journal Article In: Talanta, vol. 72, no. 2, pp. 600–606, 2007, ISSN: 0039-9140. @article{Rahmi2007,
title = {Multielement determination of trace metals in seawater by ICP-MS with aid of down-sized chelating resin-packed minicolumn for preconcentration.},
author = {Rahmi, Dwinna and Zhu, Yanbei and Fujimori, Eiji and Umemura, Tomonari and Haraguchi, Hiroki.},
doi = {10.1016/j.talanta.2006.11.023},
issn = {0039-9140},
year = {2007},
date = {2007-01-01},
journal = {Talanta},
volume = {72},
number = {2},
pages = {600--606},
publisher = {Elsevier B.V.},
abstract = {Multi-element trace metal detn. in seawater was done by inductively coupled plasma mass spectrometry (ICP-MS) following pre-concn. in down-sized, chelating resin-packed mini-column. The down-sized, chelating resin-packed mini-column was constructed with 2 syringe filters (DISMIC 13HP and Millex-LH) and an iminodiacetate chelating resin (Chelex 100, 200-400 mesh) with which trace metals in 50 mL seawater were concd. into 0.50 mL 2 M HNO3 to achieve a 100-fold trace metal pre-concn. A 0.50 mL anal. soln. was subjected to ICP-MS equipped with a MicroMist nebulizer for micro-sample introduction and multi-element detn. Pre-concn. and elution parameters (sample loading flow rate, amt. of 1 M ammonium acetate for matrix element elimination, amt. of 2 M HNO3 to elute trace metals) were optimized to obtain good recovery and anal. detection limits. Results for V, Mn, Co, Ni, Cu, Zn, Mo, Cd, Pb, and U in 3 types of seawater certified ref. materials (CRM; CASS-3, NASS-4, NASS-5) agreed well with certified values. Obsd. rare earth element (REE) concns. in these seawater CRM were also consistent with ref. values; thus, compiled ref. values for REE concns. in CASS-3, NASS-4, and NASS-5 were proposed, based on obsd. values and REE ref. data for these CRM. [on SciFinder(R)]},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Multi-element trace metal detn. in seawater was done by inductively coupled plasma mass spectrometry (ICP-MS) following pre-concn. in down-sized, chelating resin-packed mini-column. The down-sized, chelating resin-packed mini-column was constructed with 2 syringe filters (DISMIC 13HP and Millex-LH) and an iminodiacetate chelating resin (Chelex 100, 200-400 mesh) with which trace metals in 50 mL seawater were concd. into 0.50 mL 2 M HNO3 to achieve a 100-fold trace metal pre-concn. A 0.50 mL anal. soln. was subjected to ICP-MS equipped with a MicroMist nebulizer for micro-sample introduction and multi-element detn. Pre-concn. and elution parameters (sample loading flow rate, amt. of 1 M ammonium acetate for matrix element elimination, amt. of 2 M HNO3 to elute trace metals) were optimized to obtain good recovery and anal. detection limits. Results for V, Mn, Co, Ni, Cu, Zn, Mo, Cd, Pb, and U in 3 types of seawater certified ref. materials (CRM; CASS-3, NASS-4, NASS-5) agreed well with certified values. Obsd. rare earth element (REE) concns. in these seawater CRM were also consistent with ref. values; thus, compiled ref. values for REE concns. in CASS-3, NASS-4, and NASS-5 were proposed, based on obsd. values and REE ref. data for these CRM. [on SciFinder(R)] |
Hasegawa, Takuya; Wakita, Yoshinori; Zhu, Yanbei; Matsuura, Hirotaka; Haraguchi, Hiroki; Umemura, Tomonari. Speciation of human serum proteins based on trace metal mapping analysis by CIM monolithic disk column HPLC/ICP-MS in complement with off-line MALDI-TOF-MS analysis. Journal Article In: Bulletin of the Chemical Society of Japan, vol. 80, no. 3, pp. 503–506, 2007, ISSN: 0009-2673. @article{Hasegawa2007,
title = {Speciation of human serum proteins based on trace metal mapping analysis by CIM monolithic disk column HPLC/ICP-MS in complement with off-line MALDI-TOF-MS analysis.},
author = {Hasegawa, Takuya and Wakita, Yoshinori and Zhu, Yanbei and Matsuura, Hirotaka and Haraguchi, Hiroki and Umemura, Tomonari.},
doi = {10.1246/bcsj.80.503},
issn = {0009-2673},
year = {2007},
date = {2007-01-01},
journal = {Bulletin of the Chemical Society of Japan},
volume = {80},
number = {3},
pages = {503--506},
publisher = {Chemical Society of Japan},
abstract = {A multiply hyphenated HPLC/UV/ICP-MS system equipped with a fraction collection valve for subsequent MALDI-TOF-MS anal. was constructed, and its applicability to the speciation of metalloproteins in human serum was evaluated. A weak anion-exchange CIM monolithic disk column was employed for protein sepn., in which gradient elution of proteins with volatile salts was carried out while taking into account the compatibility with ICP-MS instrument. As a result of optimization, representative serum proteins, such as $gamma$-globulin ($gamma$Gb), albumin (Ab), ceruloplasmin (Cp), transferrin (Tf), and $alpha$2-macroglobulin ($alpha$2Mgb), were sepd. on the disk column with a linear concn. gradient of CH3COONH4 in 20 mM Tris-HCl buffer (pH 7.4). These proteins, which were primarily assigned by UV absorption at 280 nm, were clearly identified with online multielement detection using ICP-MS as well as with off-line MALDI-TOF-MS anal. of each successive fraction collected. It was concluded that the present multiply hyphenated system will be useful for identifying proteins in biol. samples. [on SciFinder(R)]},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
A multiply hyphenated HPLC/UV/ICP-MS system equipped with a fraction collection valve for subsequent MALDI-TOF-MS anal. was constructed, and its applicability to the speciation of metalloproteins in human serum was evaluated. A weak anion-exchange CIM monolithic disk column was employed for protein sepn., in which gradient elution of proteins with volatile salts was carried out while taking into account the compatibility with ICP-MS instrument. As a result of optimization, representative serum proteins, such as $gamma$-globulin ($gamma$Gb), albumin (Ab), ceruloplasmin (Cp), transferrin (Tf), and $alpha$2-macroglobulin ($alpha$2Mgb), were sepd. on the disk column with a linear concn. gradient of CH3COONH4 in 20 mM Tris-HCl buffer (pH 7.4). These proteins, which were primarily assigned by UV absorption at 280 nm, were clearly identified with online multielement detection using ICP-MS as well as with off-line MALDI-TOF-MS anal. of each successive fraction collected. It was concluded that the present multiply hyphenated system will be useful for identifying proteins in biol. samples. [on SciFinder(R)] |
Hasegawa, Takuya; Ishise, Jotaro; Fukumoto, Yasuharu; Matsuura, Hirotaka; Zhu, Yanbei; Umemura, Tomonari; Haraguchi, Hiroki; Yamamoto, Kazuhito; Naoe, Tomoki. Chemical speciation of arsenic species in human blood serum by liquid chromatography using a phosphatidylcholine-coated ODS column with detection by ICP-MS. Journal Article In: Bulletin of the Chemical Society of Japan, vol. 80, no. 3, pp. 498–502, 2007, ISSN: 0009-2673. @article{Hasegawa2007a,
title = {Chemical speciation of arsenic species in human blood serum by liquid chromatography using a phosphatidylcholine-coated ODS column with detection by ICP-MS.},
author = {Hasegawa, Takuya and Ishise, Jotaro and Fukumoto, Yasuharu and Matsuura, Hirotaka and Zhu, Yanbei and Umemura, Tomonari and Haraguchi, Hiroki and Yamamoto, Kazuhito and Naoe, Tomoki.},
doi = {10.1246/bcsj.80.498},
issn = {0009-2673},
year = {2007},
date = {2007-01-01},
journal = {Bulletin of the Chemical Society of Japan},
volume = {80},
number = {3},
pages = {498--502},
publisher = {Chemical Society of Japan},
abstract = {Chem. speciation of arsenic species in human blood serum was performed by HPLC/inductively coupled plasma mass spectrometry (HPLC/ICP-MS) with direct sample injection, where an octadecylsilyl silica (ODS) column coated with phosphatidylcholine (PC) (hereafter known as "PC-coated ODS column") was used as the sepn. column. In arsenic species anal., a citrate buffer soln. (pH 4.0) was used as the mobile phase, in which the following reagents were added: sodium 1-dodecanesulfonate (SDS), tetramethylammonium hydroxide (TMAH), which are ion-pair reagents to sep. inorg. and org. arsenic species, and 3-[(3-cholamidopropyl)-dimethylammonio]-1-propane sulfonate (CHAPS), which is a protein-solubilizing agent to prevent adsorption of proteins on the column. As a result of optimization, five representative arsenic species spiked in human blood serum ref. material could be sepd. from each other within 5 min on the PC-coated ODS column by elution with a 5 mM citrate buffer (pH 4.0) contg. 5 mM SDS, 5 mM THAH, and 0.2 mM CHAPS. The detection limits obtained by ICP-MS were 3.1, 2.7, 4.5, 2.5, and 2.5 ng of As g-1 for arsenate (iAsV), arsenite (iAsIII), monomethylarsonic acid (MMA), dimethylarsenic acid (DMA), and arsenobetaine (AB), resp., when the injection vol. was 20 $mu$L. The present sepn. system was also applied to speciation anal. of arsenic species in human blood serum collected from a leukemia patient after therapeutic treatment with arsenic. [on SciFinder(R)]},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Chem. speciation of arsenic species in human blood serum was performed by HPLC/inductively coupled plasma mass spectrometry (HPLC/ICP-MS) with direct sample injection, where an octadecylsilyl silica (ODS) column coated with phosphatidylcholine (PC) (hereafter known as "PC-coated ODS column") was used as the sepn. column. In arsenic species anal., a citrate buffer soln. (pH 4.0) was used as the mobile phase, in which the following reagents were added: sodium 1-dodecanesulfonate (SDS), tetramethylammonium hydroxide (TMAH), which are ion-pair reagents to sep. inorg. and org. arsenic species, and 3-[(3-cholamidopropyl)-dimethylammonio]-1-propane sulfonate (CHAPS), which is a protein-solubilizing agent to prevent adsorption of proteins on the column. As a result of optimization, five representative arsenic species spiked in human blood serum ref. material could be sepd. from each other within 5 min on the PC-coated ODS column by elution with a 5 mM citrate buffer (pH 4.0) contg. 5 mM SDS, 5 mM THAH, and 0.2 mM CHAPS. The detection limits obtained by ICP-MS were 3.1, 2.7, 4.5, 2.5, and 2.5 ng of As g-1 for arsenate (iAsV), arsenite (iAsIII), monomethylarsonic acid (MMA), dimethylarsenic acid (DMA), and arsenobetaine (AB), resp., when the injection vol. was 20 $mu$L. The present sepn. system was also applied to speciation anal. of arsenic species in human blood serum collected from a leukemia patient after therapeutic treatment with arsenic. [on SciFinder(R)] |
Hasegawa, Takuya; Fukumoto, Yasuharu; Ishise, Jotaro; Hattori, Ryota; Zhu, Yanbei; Umemura, Tomonari; Haraguchi, Hiroki. Separation characteristics of a phosphatidylcholine-coated ODS column for direct sample injection analysis of biological fluid samples. Journal Article In: Bulletin of the Chemical Society of Japan, vol. 80, no. 2, pp. 329–334, 2007, ISSN: 0009-2673. @article{Hasegawa2007b,
title = {Separation characteristics of a phosphatidylcholine-coated ODS column for direct sample injection analysis of biological fluid samples.},
author = {Hasegawa, Takuya and Fukumoto, Yasuharu and Ishise, Jotaro and Hattori, Ryota and Zhu, Yanbei and Umemura, Tomonari and Haraguchi, Hiroki.},
doi = {10.1246/bcsj.80.329},
issn = {0009-2673},
year = {2007},
date = {2007-01-01},
journal = {Bulletin of the Chemical Society of Japan},
volume = {80},
number = {2},
pages = {329--334},
publisher = {Chemical Society of Japan},
abstract = {An octadecylsilyl silica (ODS) column coated with phosphatidylcholine (PC) was prepd. by using a dynamic coating method, and its sepn. characteristics were evaluated for direct sample injection anal. of biol. fluids. First, fundamental sepn. behaviors of various kinds of large and small mols./ions were examd. by HPLC using the PC-coated ODS column with UV absorption detection, for which pure water was used as a mobile phase. In the expts., proteins (large mols.) were rapidly eluted in the range of 2.07 min (dead time)-3.20 min, while small mols., such as inorg. anions, amino acids, org. acids, and org. drugs, were eluted after 3.50 min. The fact that proteins and small mols./ions were sepd. on the PC-coated ODS column suggested that the present column can be used for direct sample injection anal. of biol. fluid samples, such as urine and blood serum. Thus, the PC-coated ODS column was used in the anal. of arsenic species in urine and in the anal. of nicotinamide, theophylline, tryptophan, and caffeine in a model blood serum soln. without any sample pretreatment. [on SciFinder(R)]},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
An octadecylsilyl silica (ODS) column coated with phosphatidylcholine (PC) was prepd. by using a dynamic coating method, and its sepn. characteristics were evaluated for direct sample injection anal. of biol. fluids. First, fundamental sepn. behaviors of various kinds of large and small mols./ions were examd. by HPLC using the PC-coated ODS column with UV absorption detection, for which pure water was used as a mobile phase. In the expts., proteins (large mols.) were rapidly eluted in the range of 2.07 min (dead time)-3.20 min, while small mols., such as inorg. anions, amino acids, org. acids, and org. drugs, were eluted after 3.50 min. The fact that proteins and small mols./ions were sepd. on the PC-coated ODS column suggested that the present column can be used for direct sample injection anal. of biol. fluid samples, such as urine and blood serum. Thus, the PC-coated ODS column was used in the anal. of arsenic species in urine and in the anal. of nicotinamide, theophylline, tryptophan, and caffeine in a model blood serum soln. without any sample pretreatment. [on SciFinder(R)] |
Yang, Bingcheng; Takeuchi, Masaki; Dasgupta, Purnendu K; Umemura, Tomonari; Ueki, Yuji; Tsunoda, Kin-Ichi. Tailoring elution of tetraalkylammonium ions. Ideal electrostatic selectivity elution order on a polymeric ion exchanger. Journal Article In: Analytical Chemistry, vol. 79, no. 2, pp. 769–772, 2007, ISSN: 0003-2700. @article{Yang2007,
title = {Tailoring elution of tetraalkylammonium ions. Ideal electrostatic selectivity elution order on a polymeric ion exchanger.},
author = {Yang, Bingcheng and Takeuchi, Masaki and Dasgupta, Purnendu K and Umemura, Tomonari and Ueki, Yuji and Tsunoda, Kin-Ichi.},
doi = {10.1021/ac061648i},
issn = {0003-2700},
year = {2007},
date = {2007-01-01},
journal = {Analytical Chemistry},
volume = {79},
number = {2},
pages = {769--772},
publisher = {American Chemical Society},
abstract = {Although ion exchange is often depicted as a process driven by electrostatic forces, ionic solvation or hydrophobic forces contribute greatly to ion exchange selectivity and is often the dominant factor. On a variety of com. anion exchange columns, monovalent ClO4- elutes after doubly charged SO42- and even triply charged PO43-. For identically charged alkali metal ions, electrostatic charge densities based on crystal radii would suggest Li+ to be the most strongly retained on a cation exchanger. In practice, it is typically the least strongly held cation on most cation exchangers, because of its very high hydration energy and with most eluents its capacity factor approaches zero. Even when the ion is very poorly solvated, as with tetraalkylammonium (NR4+) cations, there has never been a report on a polymeric ion exchanger of an ideal electrostatic selectivity order where NR4+ cations elute in their increasing charge d. order: R = Bu 1st, followed by Pr, Et, and last, Me. This selectivity order is easily achieved on recently described methracrylate-based monolithic capillary cation exchange columns (Ueki, Y.; Umemura, T.; Li, J. X.; Odake, T; Tsunoda, K. Anal. Chem. 2004, 76, 7007-7012) with minor amts. of hydroorg. modifiers. Indeed, under such conditions, Li+ (and other alkali cations) elutes after NMe4+. [on SciFinder(R)]},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Although ion exchange is often depicted as a process driven by electrostatic forces, ionic solvation or hydrophobic forces contribute greatly to ion exchange selectivity and is often the dominant factor. On a variety of com. anion exchange columns, monovalent ClO4- elutes after doubly charged SO42- and even triply charged PO43-. For identically charged alkali metal ions, electrostatic charge densities based on crystal radii would suggest Li+ to be the most strongly retained on a cation exchanger. In practice, it is typically the least strongly held cation on most cation exchangers, because of its very high hydration energy and with most eluents its capacity factor approaches zero. Even when the ion is very poorly solvated, as with tetraalkylammonium (NR4+) cations, there has never been a report on a polymeric ion exchanger of an ideal electrostatic selectivity order where NR4+ cations elute in their increasing charge d. order: R = Bu 1st, followed by Pr, Et, and last, Me. This selectivity order is easily achieved on recently described methracrylate-based monolithic capillary cation exchange columns (Ueki, Y.; Umemura, T.; Li, J. X.; Odake, T; Tsunoda, K. Anal. Chem. 2004, 76, 7007-7012) with minor amts. of hydroorg. modifiers. Indeed, under such conditions, Li+ (and other alkali cations) elutes after NMe4+. [on SciFinder(R)] |
Fujiwara, Kitao; Hirokawa, Shun; Aoki, Motohide. Optical parameter dependence of fluorescence correlation spectrometry without using magnification tools. Journal Article In: Analytical Sciences, vol. 23, no. 10, pp. 1237–1239, 2007, ISSN: 0910-6340. @article{Fujiwara2007,
title = {Optical parameter dependence of fluorescence correlation spectrometry without using magnification tools.},
author = {Kitao Fujiwara and Shun Hirokawa and Motohide. Aoki},
doi = {10.2116/analsci.23.1237},
issn = {0910-6340},
year = {2007},
date = {2007-01-01},
journal = {Analytical Sciences},
volume = {23},
number = {10},
pages = {1237--1239},
publisher = {Japan Society for Analytical Chemistry},
abstract = {The performance of fluorescence correlation spectrometry (FCS) was examd. for studying the solns. suspended with the fluorescent particles of various sizes from 50 nm to 10 $mu$m in diam. and for different sizes of pinholes: the particles were made to move by simply stirring the soln. in the quartz fluorescence cuvette. Without using any magnification tool for the optical image, this FCS system successfully distinguishes images with a size of smaller than 1 $mu$m. This system was applied for detn. of the sizes of microalgae. [on SciFinder(R)]},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
The performance of fluorescence correlation spectrometry (FCS) was examd. for studying the solns. suspended with the fluorescent particles of various sizes from 50 nm to 10 $mu$m in diam. and for different sizes of pinholes: the particles were made to move by simply stirring the soln. in the quartz fluorescence cuvette. Without using any magnification tool for the optical image, this FCS system successfully distinguishes images with a size of smaller than 1 $mu$m. This system was applied for detn. of the sizes of microalgae. [on SciFinder(R)] |
Fujiwara, Kitao; Ishige, Yuko; Inoue, Yu-Ichi; Taigo, Sunao; Sasaki, Takana; Aoki, Motohide; Shirasaki, Hidekazu; Furuno, Masahiro. Effects of derivaization on solar-induced decomposition of polycyclic aromatic hydrocarbons in aqueous media Journal Article In: Journal of environmental science and health. Part A, Toxic/hazardous substances &amp; environmental engineering, vol. 42, no. 3, pp. 225–2230, 2007, ISSN: 1093-4529. @article{Fujiwara2007a,
title = {Effects of derivaization on solar-induced decomposition of polycyclic aromatic hydrocarbons in aqueous media},
author = {Kitao Fujiwara and Yuko Ishige and Yu-Ichi Inoue and Sunao Taigo and Takana Sasaki and Motohide Aoki and Hidekazu Shirasaki and Masahiro. Furuno},
doi = {10.1080/10934520601131284},
issn = {1093-4529},
year = {2007},
date = {2007-01-01},
journal = {Journal of environmental science and health. Part A, Toxic/hazardous substances & environmental engineering},
volume = {42},
number = {3},
pages = {225--2230},
publisher = {Taylor & Francis, Inc.},
abstract = {The solar-induced decompn. of 10 polycyclic arom. hydrocarbons (PAHs) was obsd. in aq. media. All 10 PAHs obsd. were half-decompd. within 120 min. Among anthracene derivs., the decompn. rates were: anthracene = 1-methylanthracene < 2-methylanthracene < 9-methylanthracene < 9,10-dimethylanthracene ∼ 2-aminoanthracene. The addn. of com. humic acid had no effect on the decompn. rates of these PAHs. Deuterium water also hastened the decompn. of PAH. The products obtained by the solar radiation of PAH after extn. to DCM were mainly ketone and hydroxyl derivs. To explain these results, reactivities and electron charges at the constituent carbon atoms in each anthracene deriv. were examd. by an ab initio MO calcn. method. [on SciFinder(R)]},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
The solar-induced decompn. of 10 polycyclic arom. hydrocarbons (PAHs) was obsd. in aq. media. All 10 PAHs obsd. were half-decompd. within 120 min. Among anthracene derivs., the decompn. rates were: anthracene = 1-methylanthracene < 2-methylanthracene < 9-methylanthracene < 9,10-dimethylanthracene ∼ 2-aminoanthracene. The addn. of com. humic acid had no effect on the decompn. rates of these PAHs. Deuterium water also hastened the decompn. of PAH. The products obtained by the solar radiation of PAH after extn. to DCM were mainly ketone and hydroxyl derivs. To explain these results, reactivities and electron charges at the constituent carbon atoms in each anthracene deriv. were examd. by an ab initio MO calcn. method. [on SciFinder(R)] |
2006 |
Umemura, Tomonari; Hotta, Hiroki; Abe, Takahiko; Takahashi, Yoshihito; Takiguchi, Hiromi; Uehara, Masayuki; Odake, Tamao; Tsunoda, Kin-ichi. Slab optical waveguide high-acidity sensor based on an absorbance change of protoporphyrin IX. Journal Article In: Analytical Chemistry, vol. 78, no. 21, pp. 7511–7516, 2006, ISSN: 0003-2700. @article{Umemura2006,
title = {Slab optical waveguide high-acidity sensor based on an absorbance change of protoporphyrin IX.},
author = {Umemura, Tomonari and Hotta, Hiroki and Abe, Takahiko and Takahashi, Yoshihito and Takiguchi, Hiromi and Uehara, Masayuki and Odake, Tamao and Tsunoda, Kin-ichi.},
doi = {10.1021/ac0606150},
issn = {0003-2700},
year = {2006},
date = {2006-01-01},
journal = {Analytical Chemistry},
volume = {78},
number = {21},
pages = {7511--7516},
publisher = {American Chemical Society},
abstract = {A sensitive and fast-responsive evanescent wave absorption sensor was constructed for pH measurements in highly acidic ranges. This sensor is based on a pH-dependent color change of protoporphyrin IX (PPIX). For the sensitive detection, a visible attenuated total reflection spectrometer with a slab optical waveguide (SOWG) was lab.-made, and the guiding layer surface was modified with a PPIX-immobilized acrylamide-based thin membrane. The sensing membrane with a thickness of ∼1 $mu$m was directly fabricated on the SOWG glass surface by copolymn. of acrylamide, N,N'-methylene bisacrylamide, and PPIX in the narrow space confined by a cover plate. PPIX possesses two double bonds in its structure, and so it can be covalently incorporated into the membrane. The response characteristics of the PPIX-immobilized optode membrane were explored using aq. solns. with different concns. of HNO3 or HCl. The optode membrane provided characteristic Soret band absorption spectra depending on the hydrogen ion concn.; the absorbance at 410 nm increased with increasing the concns. at 0.15-2 M, corresponding to the range of pH -0.3 to 0.8. The absorption signal reached 90% of its final value within 10 s, while the absorption signal was quite readily returned to background level simply by passing 2 mL of distd. water through a flow cell with a vol. of 16.5 $mu$L placed on the SOWG. Due to the rapid response and reversibility, this sensor could be operated in a flow-through mode as well as in a conventional static mode, where deionized water was conveniently used as a carrier and conditioning soln. In terms of the stability and precision, this sensor showed no significant change in response even after 100 assays and after being stored in a dry condition for over 6 mo. Relative std. deviations for 10 replicate measurements were <1.8% in the linear range, and the detection limit calcd. from 3 times of the std. deviation was 0.02 pH unit. [on SciFinder(R)]},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
A sensitive and fast-responsive evanescent wave absorption sensor was constructed for pH measurements in highly acidic ranges. This sensor is based on a pH-dependent color change of protoporphyrin IX (PPIX). For the sensitive detection, a visible attenuated total reflection spectrometer with a slab optical waveguide (SOWG) was lab.-made, and the guiding layer surface was modified with a PPIX-immobilized acrylamide-based thin membrane. The sensing membrane with a thickness of ∼1 $mu$m was directly fabricated on the SOWG glass surface by copolymn. of acrylamide, N,N'-methylene bisacrylamide, and PPIX in the narrow space confined by a cover plate. PPIX possesses two double bonds in its structure, and so it can be covalently incorporated into the membrane. The response characteristics of the PPIX-immobilized optode membrane were explored using aq. solns. with different concns. of HNO3 or HCl. The optode membrane provided characteristic Soret band absorption spectra depending on the hydrogen ion concn.; the absorbance at 410 nm increased with increasing the concns. at 0.15-2 M, corresponding to the range of pH -0.3 to 0.8. The absorption signal reached 90% of its final value within 10 s, while the absorption signal was quite readily returned to background level simply by passing 2 mL of distd. water through a flow cell with a vol. of 16.5 $mu$L placed on the SOWG. Due to the rapid response and reversibility, this sensor could be operated in a flow-through mode as well as in a conventional static mode, where deionized water was conveniently used as a carrier and conditioning soln. In terms of the stability and precision, this sensor showed no significant change in response even after 100 assays and after being stored in a dry condition for over 6 mo. Relative std. deviations for 10 replicate measurements were <1.8% in the linear range, and the detection limit calcd. from 3 times of the std. deviation was 0.02 pH unit. [on SciFinder(R)] |
Umemura, Tomonari; Ueki, Yuji; Tsunoda, Kin-ichi; Katakai, Akio; Tamada, Masao; Haraguchi, Hiroki. Preparation and characterization of methacrylate-based semi-micro monoliths for high-throughput bioanalysis. Journal Article In: Analytical and Bioanalytical Chemistry, vol. 386, no. 3, pp. 566–571, 2006, ISSN: 1618-2642. @article{Umemura2006a,
title = {Preparation and characterization of methacrylate-based semi-micro monoliths for high-throughput bioanalysis.},
author = {Umemura, Tomonari and Ueki, Yuji and Tsunoda, Kin-ichi and Katakai, Akio and Tamada, Masao and Haraguchi, Hiroki.},
doi = {10.1007/s00216-006-0425-2},
issn = {1618-2642},
year = {2006},
date = {2006-01-01},
journal = {Analytical and Bioanalytical Chemistry},
volume = {386},
number = {3},
pages = {566--571},
publisher = {Springer},
abstract = {Hexyl methacrylate (HMA)-based monolithic semi-micro columns were prepd. by in situ polymn. within the confines of 1.02-mm-i.d. silicosteel tubing for reversed-phase and/or pptn.-redissoln. liq. chromatog. Practically useful monolithic columns with adequate sepn. efficiency, high permeability, and good mech. strength were successfully obtained using a polymn. mixt. comprising 24% hexyl methacrylate (HMA), 6% ethylene dimethacrylate (EDMA), 44.5% 1-propanol, and 25.5% 1,4-butanediol. The column performance was evaluated through the sepns. of a series of alkylbenzenes. At a normal flow rate of 50 $mu$L min-1, the produced HMA-based monolithic columns typically exhibited 3000 theor. plates for a 20-cm-long column, and the pressure drop was generally less than 1 MPa per 20 cm. The monolithic columns were resistant to at least 15 MPa, and could be properly operated at 15-20 times higher flow rate than normal, reducing the sepn. time to 1/15-1/20. The HMA-based monolithic columns were applied to rapid and efficient sepns. of proteins such as RNase A, cytochrome c, transferrin, and ovalbumin in the pptn.-redissoln. mode. Using a CH3CN gradient elution at a flow rate of 1000 $mu$L min-1, four proteins were baseline sepd. within 20 s. [on SciFinder(R)]},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Hexyl methacrylate (HMA)-based monolithic semi-micro columns were prepd. by in situ polymn. within the confines of 1.02-mm-i.d. silicosteel tubing for reversed-phase and/or pptn.-redissoln. liq. chromatog. Practically useful monolithic columns with adequate sepn. efficiency, high permeability, and good mech. strength were successfully obtained using a polymn. mixt. comprising 24% hexyl methacrylate (HMA), 6% ethylene dimethacrylate (EDMA), 44.5% 1-propanol, and 25.5% 1,4-butanediol. The column performance was evaluated through the sepns. of a series of alkylbenzenes. At a normal flow rate of 50 $mu$L min-1, the produced HMA-based monolithic columns typically exhibited 3000 theor. plates for a 20-cm-long column, and the pressure drop was generally less than 1 MPa per 20 cm. The monolithic columns were resistant to at least 15 MPa, and could be properly operated at 15-20 times higher flow rate than normal, reducing the sepn. time to 1/15-1/20. The HMA-based monolithic columns were applied to rapid and efficient sepns. of proteins such as RNase A, cytochrome c, transferrin, and ovalbumin in the pptn.-redissoln. mode. Using a CH3CN gradient elution at a flow rate of 1000 $mu$L min-1, four proteins were baseline sepd. within 20 s. [on SciFinder(R)] |
Hasegawa, Takuya; Sugita, Masaru; Takatani, Kohei; Matsuura, Hirotaka; Umemura, Tomonari; Haraguchi, Hiroki. Assay of alkaline phosphatase in salmon egg cell cytoplasm with fluorescence detection of enzymatic activity and zinc detection by ICP-MS in relation to metallomics research. Journal Article In: Bulletin of the Chemical Society of Japan, vol. 79, no. 8, pp. 1211–1214, 2006, ISSN: 0009-2673. @article{Hasegawa2006,
title = {Assay of alkaline phosphatase in salmon egg cell cytoplasm with fluorescence detection of enzymatic activity and zinc detection by ICP-MS in relation to metallomics research.},
author = {Hasegawa, Takuya and Sugita, Masaru and Takatani, Kohei and Matsuura, Hirotaka and Umemura, Tomonari and Haraguchi, Hiroki.},
doi = {10.1246/bcsj.79.1211},
issn = {0009-2673},
year = {2006},
date = {2006-01-01},
journal = {Bulletin of the Chemical Society of Japan},
volume = {79},
number = {8},
pages = {1211--1214},
publisher = {Chemical Society of Japan},
abstract = {Assay of alk. phosphatase (ALP) in salmon egg cell cytoplasm was performed by size exclusion chromatog. (SEC) with fluorescence detection of enzymic activity and element-selective detection of zinc by ICP-MS, where 4-methylumbelliferyl phosphate (4-MUP) was used as the substrate for the enzymic reaction of ALP. Two peaks were obsd. at retention times of ∼21 and 27 min in the fluorescence-detected SEC chromatogram for salmon egg cell cytoplasm dild. 10-fold with 0.1 M Tris-HNO3 buffer soln., corresponding to the mol. wts. (MWs) of ≥300 and 100 kDa, resp. In the 66Zn-detected chromatogram for the same sample, a broad peak with a shoulder on the side of longer retention time was obsd. at ∼21 min (MW ≥300 kDa). When salmon egg cell cytoplasm was dild. 10-fold with pure water or 0.01 M Tris-HNO3 buffer soln., pptn. occurred. The supernatant obtained after filtration produced only one clear peak at a retention time of ∼27 min in the fluorescence-detected chromatogram, at which the peak corresponding to zinc was also obsd. in the Zn-detected chromatogram. Therefore, the peak near 27 min was assigned to hydrophilic ALP in the salmon egg cell cytoplasm. Furthermore, the concn. of hydrophilic ALP (MW ∼100 kDa) in the salmon egg cell cytoplasm was about 350 ng g-1, which was detd. as an E. coli ALP-equiv. concn. by fluorescence intensity measurements. [on SciFinder(R)]},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Assay of alk. phosphatase (ALP) in salmon egg cell cytoplasm was performed by size exclusion chromatog. (SEC) with fluorescence detection of enzymic activity and element-selective detection of zinc by ICP-MS, where 4-methylumbelliferyl phosphate (4-MUP) was used as the substrate for the enzymic reaction of ALP. Two peaks were obsd. at retention times of ∼21 and 27 min in the fluorescence-detected SEC chromatogram for salmon egg cell cytoplasm dild. 10-fold with 0.1 M Tris-HNO3 buffer soln., corresponding to the mol. wts. (MWs) of ≥300 and 100 kDa, resp. In the 66Zn-detected chromatogram for the same sample, a broad peak with a shoulder on the side of longer retention time was obsd. at ∼21 min (MW ≥300 kDa). When salmon egg cell cytoplasm was dild. 10-fold with pure water or 0.01 M Tris-HNO3 buffer soln., pptn. occurred. The supernatant obtained after filtration produced only one clear peak at a retention time of ∼27 min in the fluorescence-detected chromatogram, at which the peak corresponding to zinc was also obsd. in the Zn-detected chromatogram. Therefore, the peak near 27 min was assigned to hydrophilic ALP in the salmon egg cell cytoplasm. Furthermore, the concn. of hydrophilic ALP (MW ∼100 kDa) in the salmon egg cell cytoplasm was about 350 ng g-1, which was detd. as an E. coli ALP-equiv. concn. by fluorescence intensity measurements. [on SciFinder(R)] |
Takiguchi, Hiromi; Tsubata, Azusa; Miyata, Makoto; Odake, Tamao; Hotta, Hiroki; Umemura, Tomonari; Tsunoda, Kin-ichi. Liquid core waveguide spectrophotometry for the sensitive determination of nitrite in river water samples. Journal Article In: Analytical Sciences, vol. 22, no. 7, pp. 1017–1019, 2006, ISSN: 0910-6340. @article{Takiguchi2006,
title = {Liquid core waveguide spectrophotometry for the sensitive determination of nitrite in river water samples.},
author = {Takiguchi, Hiromi and Tsubata, Azusa and Miyata, Makoto and Odake, Tamao and Hotta, Hiroki and Umemura, Tomonari and Tsunoda, Kin-ichi.},
doi = {10.2116/analsci.22.1017},
issn = {0910-6340},
year = {2006},
date = {2006-01-01},
journal = {Analytical Sciences},
volume = {22},
number = {7},
pages = {1017--1019},
publisher = {Japan Society for Analytical Chemistry},
abstract = {A flow injection anal. system was built with a liq. core waveguide spectrophotometric detector using an 80 cm Teflon AF-1600 capillary tube (2,2-bistrifluoromethyl-4,5-difluoro-1,3-dioxole/tetrafluoroethylene). The system was applied to det. nitrite ion in river water samples. The lower limit of detection for nitrite was 2.1 nmol dm-3 (0.1 ng dm-3 as NO2-) and the relative std. deviation of measurements was typically 0.56% (n = 5) at 0.21 $mu$mol dm-3. [on SciFinder(R)]},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
A flow injection anal. system was built with a liq. core waveguide spectrophotometric detector using an 80 cm Teflon AF-1600 capillary tube (2,2-bistrifluoromethyl-4,5-difluoro-1,3-dioxole/tetrafluoroethylene). The system was applied to det. nitrite ion in river water samples. The lower limit of detection for nitrite was 2.1 nmol dm-3 (0.1 ng dm-3 as NO2-) and the relative std. deviation of measurements was typically 0.56% (n = 5) at 0.21 $mu$mol dm-3. [on SciFinder(R)] |
Ueki, Yuji; Umemura, Tomonari; Iwashita, Yoshikazu; Odake, Tamao; Haraguchi, Hiroki; Tsunoda, Kin-Ichi. Preparation of low flow-resistant methacrylate-based monolithic stationary phases of different hydrophobicity and the application to rapid reversed-phase liquid chromatographic separation of alkylbenzenes at high flow rate and elevated temperature. Journal Article In: Journal of Chromatography A, vol. 1106, no. 1-2, pp. 106–111, 2006, ISSN: 0021-9673. @article{Ueki2006,
title = {Preparation of low flow-resistant methacrylate-based monolithic stationary phases of different hydrophobicity and the application to rapid reversed-phase liquid chromatographic separation of alkylbenzenes at high flow rate and elevated temperature.},
author = {Ueki, Yuji and Umemura, Tomonari and Iwashita, Yoshikazu and Odake, Tamao and Haraguchi, Hiroki and Tsunoda, Kin-Ichi.},
doi = {10.1016/j.chroma.2005.08.041},
issn = {0021-9673},
year = {2006},
date = {2006-01-01},
journal = {Journal of Chromatography A},
volume = {1106},
number = {1-2},
pages = {106--111},
publisher = {Elsevier B.V.},
abstract = {Low flow-resistant alkyl methacrylate-based monolithic stationary phases of different hydrophobicity were constructed for reversed-phase capillary liq. chromatog. by thermally initiated radical polymn. of resp. methacrylate ester monomer with different alkyl chain (C2, C4, C6, C12, C18) and ethylene glycol dimethacrylate (EDMA) in a 250 $mu$m internal diam. fused silica capillary. The hydrophobicity was basically controlled by changing the length and/or the d. of the alkyl-chain, while the compn. and the ratio of porogenic solvent were adjusted to obtain highly permeable rigid monoliths with adequate column efficiency. Among the prepd. monolithic stationary phases, C18-methacrylate monoliths polymd. from a binary porogenic solvent of isoamyl alc. and 1,4-butandiol exhibited the most promising performance in terms of hydraulic resistance and column efficiency. The pressure drops of 20-cm long monolithic columns were ⪅0.4 MPa at a normal linear velocity of 1 mm/s (a flow rate of 3 $mu$L/min), and the nos. of theor. plates for alkylbenzenes mostly exceeded 3000 plates/20 cm. The produced monolithic columns had good mech. strength for high pressure and temp., and could be properly operated even at a temp. of 80° and at a pressure of at least 33 MPa. At 80°, the theor. plate nos. reached 6000 plates/20 cm because of the enhanced mass transfer. Due to the novel hydraulic resistance and mech. strength, the sepn. time could be reduced 120-fold simply by raising the flow rate and column temp. [on SciFinder(R)]},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Low flow-resistant alkyl methacrylate-based monolithic stationary phases of different hydrophobicity were constructed for reversed-phase capillary liq. chromatog. by thermally initiated radical polymn. of resp. methacrylate ester monomer with different alkyl chain (C2, C4, C6, C12, C18) and ethylene glycol dimethacrylate (EDMA) in a 250 $mu$m internal diam. fused silica capillary. The hydrophobicity was basically controlled by changing the length and/or the d. of the alkyl-chain, while the compn. and the ratio of porogenic solvent were adjusted to obtain highly permeable rigid monoliths with adequate column efficiency. Among the prepd. monolithic stationary phases, C18-methacrylate monoliths polymd. from a binary porogenic solvent of isoamyl alc. and 1,4-butandiol exhibited the most promising performance in terms of hydraulic resistance and column efficiency. The pressure drops of 20-cm long monolithic columns were ⪅0.4 MPa at a normal linear velocity of 1 mm/s (a flow rate of 3 $mu$L/min), and the nos. of theor. plates for alkylbenzenes mostly exceeded 3000 plates/20 cm. The produced monolithic columns had good mech. strength for high pressure and temp., and could be properly operated even at a temp. of 80° and at a pressure of at least 33 MPa. At 80°, the theor. plate nos. reached 6000 plates/20 cm because of the enhanced mass transfer. Due to the novel hydraulic resistance and mech. strength, the sepn. time could be reduced 120-fold simply by raising the flow rate and column temp. [on SciFinder(R)] |
Zhu, Yanbei; Itoh, Akihide; Fujimori, Eiji; Umemura, Tomonari; Haraguchi, Hiroki. Determination of rare earth elements in seawater by ICP-MS after preconcentration with a chelating resin-packed minicolumn. Journal Article In: Journal of Alloys and Compounds, vol. 408-412, pp. 985–988, 2006, ISSN: 0925-8388. @article{Zhu2006,
title = {Determination of rare earth elements in seawater by ICP-MS after preconcentration with a chelating resin-packed minicolumn.},
author = {Zhu, Yanbei and Itoh, Akihide and Fujimori, Eiji and Umemura, Tomonari and Haraguchi, Hiroki.},
doi = {10.1016/j.jallcom.2004.12.092},
issn = {0925-8388},
year = {2006},
date = {2006-01-01},
journal = {Journal of Alloys and Compounds},
volume = {408-412},
pages = {985--988},
publisher = {Elsevier B.V.},
abstract = {Rare earth elements (REEs) in seawater were preconcd. 20-fold (from 50 to 2.5 mL) by a chelating resin-packed minicolumn device and detd. by inductively coupled plasma mass spectrometry (ICP-MS). The recoveries for REEs were from 90% for Eu and Dy to 98% for Yb, and their std. deviations were <4%. The lower detection limits for REEs were from 0.06 ng/L for Lu to 0.5 ng/L for Sm. The anal. results for REEs in seawater ref. materials (NASS-5, CASS-3, and CASS-4), the Take Island coastal seawater, and the Ise Bay coastal seawater were evaluated as the REE distribution patterns with shale-normalization and deep seawater-normalization. Slight relative enrichments of heavy REEs were obsd. in the Take Island coastal seawater and the Ise Bay coastal seawater, which might be attributed to the input from the river flows contg. more dissolved heavy REEs. Pos. anomalies of Sm were found in the normalized REE distribution patterns for NASS-5, CASS-3, and CASS-4, which would be attributed to the contamination in the prepn. process of ref. materials by NRC. [on SciFinder(R)]},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Rare earth elements (REEs) in seawater were preconcd. 20-fold (from 50 to 2.5 mL) by a chelating resin-packed minicolumn device and detd. by inductively coupled plasma mass spectrometry (ICP-MS). The recoveries for REEs were from 90% for Eu and Dy to 98% for Yb, and their std. deviations were <4%. The lower detection limits for REEs were from 0.06 ng/L for Lu to 0.5 ng/L for Sm. The anal. results for REEs in seawater ref. materials (NASS-5, CASS-3, and CASS-4), the Take Island coastal seawater, and the Ise Bay coastal seawater were evaluated as the REE distribution patterns with shale-normalization and deep seawater-normalization. Slight relative enrichments of heavy REEs were obsd. in the Take Island coastal seawater and the Ise Bay coastal seawater, which might be attributed to the input from the river flows contg. more dissolved heavy REEs. Pos. anomalies of Sm were found in the normalized REE distribution patterns for NASS-5, CASS-3, and CASS-4, which would be attributed to the contamination in the prepn. process of ref. materials by NRC. [on SciFinder(R)] |
2005 |
Takiguchi, Hiromi; Odake, Tamao; Umemura, Tomonari; Hotta, Hiroki; Tsunoda, Kin-ichi. Characteristics of a liquid/liquid optical waveguide using sheath flow and its application to detect molecules at a liquid/liquid interface. Journal Article In: Analytical Sciences, vol. 21, no. 11, pp. 1269–1274, 2005, ISSN: 0910-6340. @article{Takiguchi2005,
title = {Characteristics of a liquid/liquid optical waveguide using sheath flow and its application to detect molecules at a liquid/liquid interface.},
author = {Takiguchi, Hiromi and Odake, Tamao and Umemura, Tomonari and Hotta, Hiroki and Tsunoda, Kin-ichi.},
doi = {10.2116/analsci.21.1269},
issn = {0910-6340},
year = {2005},
date = {2005-01-01},
journal = {Analytical Sciences},
volume = {21},
number = {11},
pages = {1269--1274},
publisher = {Japan Society for Analytical Chemistry},
abstract = {The formation conditions and characteristics of a liq./liq. optical waveguide (LLW) were studied using a 2-phase sheath flow, where the inner org. phase flow acted as the core and the outer aq. flow acted as the clad. In immiscible solvent systems, i.e., toluene/H2O and Et2O/H2O systems, the LLWs were formed in the range of ⪆600 of the Reynolds no. (Re), where the linear velocity of the org. solvent was much higher than that of the aq. soln. However, in a miscible solvent system, i.e., a THF/H2O system, a stable LLW was formed in the range of a much lower Re than in immiscible systems. Also, the mols. at the toluene/H2O interface of the LLW were obsd. with both fluorescence and absorbance measurement systems. In particular, the change in the fluorescence spectrum of 1-anilino-8-naphthalenesulfonate (ANS) at the interface within 1 ms was obsd. by this method, indicating the usefulness of the LLW for a fast kinetic study of a liq./liq. interface. [on SciFinder(R)]},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
The formation conditions and characteristics of a liq./liq. optical waveguide (LLW) were studied using a 2-phase sheath flow, where the inner org. phase flow acted as the core and the outer aq. flow acted as the clad. In immiscible solvent systems, i.e., toluene/H2O and Et2O/H2O systems, the LLWs were formed in the range of ⪆600 of the Reynolds no. (Re), where the linear velocity of the org. solvent was much higher than that of the aq. soln. However, in a miscible solvent system, i.e., a THF/H2O system, a stable LLW was formed in the range of a much lower Re than in immiscible systems. Also, the mols. at the toluene/H2O interface of the LLW were obsd. with both fluorescence and absorbance measurement systems. In particular, the change in the fluorescence spectrum of 1-anilino-8-naphthalenesulfonate (ANS) at the interface within 1 ms was obsd. by this method, indicating the usefulness of the LLW for a fast kinetic study of a liq./liq. interface. [on SciFinder(R)] |
Matsuura, Hirotaka; Asano, Motoki; Hasegawa, Takuya; Umemura, Tomonari; Haraguchi, Hiroki. Speciation and excretion patterns of arsenic metabolites in human urine after ingestion of edible seaweed, Hizikia fusiforme. Journal Article In: Bulletin of the Chemical Society of Japan, vol. 78, no. 11, pp. 1977–1981, 2005, ISSN: 0009-2673. @article{Matsuura2005,
title = {Speciation and excretion patterns of arsenic metabolites in human urine after ingestion of edible seaweed, Hizikia fusiforme.},
author = {Matsuura, Hirotaka and Asano, Motoki and Hasegawa, Takuya and Umemura, Tomonari and Haraguchi, Hiroki.},
doi = {10.1246/bcsj.78.1977},
issn = {0009-2673},
year = {2005},
date = {2005-01-01},
journal = {Bulletin of the Chemical Society of Japan},
volume = {78},
number = {11},
pages = {1977--1981},
publisher = {Chemical Society of Japan},
abstract = {Chem. speciation of arsenic in human urine was performed by HPLC sepn. with ICP-MS detection to investigate the urinary excretion patterns of arsenic metabolites after one-time ingestion of an edible seaweed, hijiki (Hizikia fusiforme). A Japanese male volunteer ingested one serving of ∼15 g (dry wt.) of hijiki (contg. ∼0.9 mg of arsenic), and urine samples were collected at 3-5 h intervals for the following 3 days. As a result, different urinary excretion patterns were obsd. between inorg. and methylated arsenicals. Toxic inorg. As(V) and As(III) were detected in the urine 3 h after ingestion. The highest concns. of As(V) and As(III) were obsd. at 6 and 15 h after ingestion, resp. In contrast, methylated arsenic species in the urine, such as monomethylarsonic acid (MMA), dimethylarsinic acid (DMA), and arsenobetaine (AB), began to increase 10 h after ingestion and provided the highest concns. at 21 h after ingestion. These results indicate that a large amt. of As(V) from hijiki is excreted rapidly in urine and some part of it is reduced to As(III) in the human body. As(III) may then be converted to non-toxic methylated arsenic species and excreted in urine later than inorg. ones. It can be concluded from these exptl. that detoxification of arsenic occurs in the human body through the rapid urinary excretion of toxic arsenicals or by conversion to org. methylated ones after ingestion of hijiki. [on SciFinder(R)]},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Chem. speciation of arsenic in human urine was performed by HPLC sepn. with ICP-MS detection to investigate the urinary excretion patterns of arsenic metabolites after one-time ingestion of an edible seaweed, hijiki (Hizikia fusiforme). A Japanese male volunteer ingested one serving of ∼15 g (dry wt.) of hijiki (contg. ∼0.9 mg of arsenic), and urine samples were collected at 3-5 h intervals for the following 3 days. As a result, different urinary excretion patterns were obsd. between inorg. and methylated arsenicals. Toxic inorg. As(V) and As(III) were detected in the urine 3 h after ingestion. The highest concns. of As(V) and As(III) were obsd. at 6 and 15 h after ingestion, resp. In contrast, methylated arsenic species in the urine, such as monomethylarsonic acid (MMA), dimethylarsinic acid (DMA), and arsenobetaine (AB), began to increase 10 h after ingestion and provided the highest concns. at 21 h after ingestion. These results indicate that a large amt. of As(V) from hijiki is excreted rapidly in urine and some part of it is reduced to As(III) in the human body. As(III) may then be converted to non-toxic methylated arsenic species and excreted in urine later than inorg. ones. It can be concluded from these exptl. that detoxification of arsenic occurs in the human body through the rapid urinary excretion of toxic arsenicals or by conversion to org. methylated ones after ingestion of hijiki. [on SciFinder(R)] |
Zhu, Yanbei; Hattori, Ryota; Rahmi, Dwinna; Okuda, Satoshi; Itoh, Akihide; Fujimori, Eiji; Umemura, Tomonari; Haraguchi, Hiroki. Fractional distributions of trace metals in surface water of Lake Biwa as studied by ultrafiltration and ICP-MS. Journal Article In: Bulletin of the Chemical Society of Japan, vol. 78, no. 11, pp. 1970–1976, 2005, ISSN: 0009-2673. @article{Zhu2005,
title = {Fractional distributions of trace metals in surface water of Lake Biwa as studied by ultrafiltration and ICP-MS.},
author = {Zhu, Yanbei and Hattori, Ryota and Rahmi, Dwinna and Okuda, Satoshi and Itoh, Akihide and Fujimori, Eiji and Umemura, Tomonari and Haraguchi, Hiroki.},
doi = {10.1246/bcsj.78.1970},
issn = {0009-2673},
year = {2005},
date = {2005-01-01},
journal = {Bulletin of the Chemical Society of Japan},
volume = {78},
number = {11},
pages = {1970--1976},
publisher = {Chemical Society of Japan},
abstract = {The distributions of 33 trace metals in the total dissolved fraction (TDF), small mol. wt. fraction (SMWF; <10,000 Da), and large mol. wt. fraction (LMWF; >10,000 Da) of surface water from 2 sampling stations (No. 1 and No. 2) in Lake Biwa (Japan) were studied. The concns. of trace metals in TDF and SMWF were detd. by inductively coupled plasma mass spectrometry (ICP-MS) using a lab.-made chelating resin-packed minicolumn for the preconcn. of trace metals. The concns. of trace metals in LMWF were calcd. by subtracting those in SMWF from those in TDF. The comparison between the distributions of trace metals in each fraction collected from the sampling stations No. 1 and No. 2 was made, and the enrichment factors of trace metals in LMWF were estd. It was found that sol. biogenic large mol.-metal complexes and hydrogenic particulates were predominantly distributed in LMWF of surface water from Lake Biwa. Pos. anomalies of Ce and Gd were obsd. in the shale-normalized rare earth element (REE) distribution patterns. [on SciFinder(R)]},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
The distributions of 33 trace metals in the total dissolved fraction (TDF), small mol. wt. fraction (SMWF; <10,000 Da), and large mol. wt. fraction (LMWF; >10,000 Da) of surface water from 2 sampling stations (No. 1 and No. 2) in Lake Biwa (Japan) were studied. The concns. of trace metals in TDF and SMWF were detd. by inductively coupled plasma mass spectrometry (ICP-MS) using a lab.-made chelating resin-packed minicolumn for the preconcn. of trace metals. The concns. of trace metals in LMWF were calcd. by subtracting those in SMWF from those in TDF. The comparison between the distributions of trace metals in each fraction collected from the sampling stations No. 1 and No. 2 was made, and the enrichment factors of trace metals in LMWF were estd. It was found that sol. biogenic large mol.-metal complexes and hydrogenic particulates were predominantly distributed in LMWF of surface water from Lake Biwa. Pos. anomalies of Ce and Gd were obsd. in the shale-normalized rare earth element (REE) distribution patterns. [on SciFinder(R)] |
Hasegawa, Takuya; Asano, Motoki; Takatani, Kohei; Matsuura, Hirotaka; Umemura, Tomonari; Haraguchi, Hiroki. Speciation of mercury in salmon egg cell cytoplasm in relation with metallomics research. Journal Article In: Talanta, vol. 68, no. 2, pp. 465–469, 2005, ISSN: 0039-9140. @article{Hasegawa2005,
title = {Speciation of mercury in salmon egg cell cytoplasm in relation with metallomics research.},
author = {Hasegawa, Takuya and Asano, Motoki and Takatani, Kohei and Matsuura, Hirotaka and Umemura, Tomonari and Haraguchi, Hiroki.},
doi = {10.1016/j.talanta.2005.09.038},
issn = {0039-9140},
year = {2005},
date = {2005-01-01},
journal = {Talanta},
volume = {68},
number = {2},
pages = {465--469},
publisher = {Elsevier B.V.},
abstract = {Speciation of mercury in salmon egg cell cytoplasm was investigated by surfactant-mediated high-performance liq. chromatog./inductively coupled plasma mass spectrometry (HPLC/ICP-MS), where an ODS (octadecylsilica) column coated with a bile acid deriv., CHAPS (3-[(3-cholamidopropyl)-dimethylammonio]-1-propane sulfonate), was used for species sepn. Prior to the speciation anal., total Hg in the cell cytoplasm was detd. by ICP-MS at m/z 202 in a flow injection mode. For the precise measurement, salmon egg cell cytoplasm was dild. five-fold with 0.1 M Tris (Tris(hydroxymethyl)aminomethane)-HNO3 buffer soln., and the std. addn. method was employed. Thus, the total concn. of Hg in cell cytoplasm was estd. to be 12.4 ng g-1 on the wet wt. basis. Next, the cell cytoplasm dild. five-fold with 0.1 M Tris-HNO3 buffer soln. was analyzed by surfactant-mediated HPLC with the dual detection system of a UV absorption detector and an ICP-MS instrument. Two peaks corresponding to some proteins and small mols. were mainly obsd. in those chromatograms. When salmon egg cell cytoplasm was dild. five-fold with 0.01 M Tris buffer soln. or pure water, some ppts. appeared probably because of pptn. of hydrophobic proteins in cytoplasm. After the ppts. were eliminated with a membrane filter, the filtrate was subjected to the anal. by surfactant-mediated HPLC/UV/ICP-MS. As a result, the peaks for small mol. species of Hg were clearly obsd. at the retention time near 4.0 min (corresponding to low-mol. wt. zone) in the chromatograms with UV absorption detection as well as with Hg- and S-specific ICP-MS detections. The small mol. bound with Hg was identified as cysteine through the cysteine-spiked expt. In addn., the protein fraction on the chromatogram obtained by using the CHAPS-coated ODS column was further analyzed by SEC (size exclusion chromatog.). Consequently, several protein peaks with mol. wt. of 300, 50 and 12 kDa were obsd. in all the detections of UV absorption, Hg and Se, although two peaks among them were coincident in the case of S. These results indicate that Hg in salmon egg cell cytoplasm binds with proteins contg. selenocysteine and/or cysteine residues in proteins. [on SciFinder(R)]},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Speciation of mercury in salmon egg cell cytoplasm was investigated by surfactant-mediated high-performance liq. chromatog./inductively coupled plasma mass spectrometry (HPLC/ICP-MS), where an ODS (octadecylsilica) column coated with a bile acid deriv., CHAPS (3-[(3-cholamidopropyl)-dimethylammonio]-1-propane sulfonate), was used for species sepn. Prior to the speciation anal., total Hg in the cell cytoplasm was detd. by ICP-MS at m/z 202 in a flow injection mode. For the precise measurement, salmon egg cell cytoplasm was dild. five-fold with 0.1 M Tris (Tris(hydroxymethyl)aminomethane)-HNO3 buffer soln., and the std. addn. method was employed. Thus, the total concn. of Hg in cell cytoplasm was estd. to be 12.4 ng g-1 on the wet wt. basis. Next, the cell cytoplasm dild. five-fold with 0.1 M Tris-HNO3 buffer soln. was analyzed by surfactant-mediated HPLC with the dual detection system of a UV absorption detector and an ICP-MS instrument. Two peaks corresponding to some proteins and small mols. were mainly obsd. in those chromatograms. When salmon egg cell cytoplasm was dild. five-fold with 0.01 M Tris buffer soln. or pure water, some ppts. appeared probably because of pptn. of hydrophobic proteins in cytoplasm. After the ppts. were eliminated with a membrane filter, the filtrate was subjected to the anal. by surfactant-mediated HPLC/UV/ICP-MS. As a result, the peaks for small mol. species of Hg were clearly obsd. at the retention time near 4.0 min (corresponding to low-mol. wt. zone) in the chromatograms with UV absorption detection as well as with Hg- and S-specific ICP-MS detections. The small mol. bound with Hg was identified as cysteine through the cysteine-spiked expt. In addn., the protein fraction on the chromatogram obtained by using the CHAPS-coated ODS column was further analyzed by SEC (size exclusion chromatog.). Consequently, several protein peaks with mol. wt. of 300, 50 and 12 kDa were obsd. in all the detections of UV absorption, Hg and Se, although two peaks among them were coincident in the case of S. These results indicate that Hg in salmon egg cell cytoplasm binds with proteins contg. selenocysteine and/or cysteine residues in proteins. [on SciFinder(R)] |
Hasegawa, Takuya; Umemura, Tomonari; Koide, Akira; Chiba, Koichi; Ueki, Yuji; Tsunoda, Kin-ichi; Haraguchi, Hiroki. Evaluation of an ODS column modified with zwitterionic/nonionic mixed surfactants and its application to direct injection determination of inorganic anions. Journal Article In: Analytical Sciences, vol. 21, no. 8, pp. 913–916, 2005, ISSN: 0910-6340. @article{Hasegawa2005a,
title = {Evaluation of an ODS column modified with zwitterionic/nonionic mixed surfactants and its application to direct injection determination of inorganic anions.},
author = {Hasegawa, Takuya and Umemura, Tomonari and Koide, Akira and Chiba, Koichi and Ueki, Yuji and Tsunoda, Kin-ichi and Haraguchi, Hiroki.},
doi = {10.2116/analsci.21.913},
issn = {0910-6340},
year = {2005},
date = {2005-01-01},
journal = {Analytical Sciences},
volume = {21},
number = {8},
pages = {913--916},
publisher = {Japan Society for Analytical Chemistry},
abstract = {An octadecylsilica (ODS) column modified with zwitterionic/nonionic mixed surfactants was evaluated for the direct injection detn. of inorg. anions in biol. fluids by ion chromatog. A zwitterionic surfactant (sulfobetaine-type) and a nonionic surfactant (polyoxyethylene-type) were used for a stationary-phase modification. When aq. electrolyte solns. with concns. of sub-mM to several mM were used as a mobile phase, the zwitterionic surfactant coated on the ODS surface exhibited unique sepn. selectivity for ionic species, while the nonionic surfactant coated on the ODS might have formed a hydrophilic network over the ODS surface and restricted matrix proteins from adsorbing on the stationary phase. Consequently, the mixed surfactant-modified column system allowed an efficient ion chromatog. sepn. of inorg. anions as well as a size-exclusive removal of column-fouling proteins. This sepn. system was applied to the direct injection detn. of UV-absorbing anions in human saliva. The detection limits for nitrite, nitrate, iodide and thiocyanate were 3.1, 2.7, 4.5 and 25 $mu$M, resp., with UV detection at 210 nm (injection vol.; 20 $mu$l), and their relative std. deviations for 5 replicate measurements of saliva samples spiked with 100 $mu$M each of those anions were 1.4, 0.9, 2.2 and 5.5%, resp. [on SciFinder(R)]},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
An octadecylsilica (ODS) column modified with zwitterionic/nonionic mixed surfactants was evaluated for the direct injection detn. of inorg. anions in biol. fluids by ion chromatog. A zwitterionic surfactant (sulfobetaine-type) and a nonionic surfactant (polyoxyethylene-type) were used for a stationary-phase modification. When aq. electrolyte solns. with concns. of sub-mM to several mM were used as a mobile phase, the zwitterionic surfactant coated on the ODS surface exhibited unique sepn. selectivity for ionic species, while the nonionic surfactant coated on the ODS might have formed a hydrophilic network over the ODS surface and restricted matrix proteins from adsorbing on the stationary phase. Consequently, the mixed surfactant-modified column system allowed an efficient ion chromatog. sepn. of inorg. anions as well as a size-exclusive removal of column-fouling proteins. This sepn. system was applied to the direct injection detn. of UV-absorbing anions in human saliva. The detection limits for nitrite, nitrate, iodide and thiocyanate were 3.1, 2.7, 4.5 and 25 $mu$M, resp., with UV detection at 210 nm (injection vol.; 20 $mu$l), and their relative std. deviations for 5 replicate measurements of saliva samples spiked with 100 $mu$M each of those anions were 1.4, 0.9, 2.2 and 5.5%, resp. [on SciFinder(R)] |
Ueki, Yuji; Umemura, Tomonari; Iwashita, Yoshikazu; Tsunoda, Kin-ichi; Haraguchi, Hiroki. Rapid reversed-phase separation using methacrylate-based C18 monolithic capillary columns at high flow rates and elevated temperatures. Journal Article In: Chemistry Letters, vol. 34, no. 8, pp. 1198–1199, 2005, ISSN: 0366-7022. @article{Ueki2005,
title = {Rapid reversed-phase separation using methacrylate-based C18 monolithic capillary columns at high flow rates and elevated temperatures.},
author = {Ueki, Yuji and Umemura, Tomonari and Iwashita, Yoshikazu and Tsunoda, Kin-ichi and Haraguchi, Hiroki.},
doi = {10.1246/cl.2005.1198},
issn = {0366-7022},
year = {2005},
date = {2005-01-01},
journal = {Chemistry Letters},
volume = {34},
number = {8},
pages = {1198--1199},
publisher = {Chemical Society of Japan},
abstract = {Rapid reversed-phase sepn. in the time-scale of seconds was conducted using methacrylate-based C18 monolithic capillary columns at high flow rates and elevated temps. The reversed-phase monolithic columns were prepd. by in situ polymn. of octadecyl methacrylate (ODMA) and ethylene dimethacrylate (EDMA) within the confines of a polyimide-coated fused silica capillary. When a mixt. of isoamyl alc. and 1,4-butandiol was employed as a porogenic solvent, highly permeable monolithic stationary phases with adequate sepn. efficiency were reproducibly produced. The pressure drops of 20 cm-long columns were typically below 0.4 MPa at a normal flow rate of 3 $mu$L/min (linear velocity of 1 mm/s), and the theor. plate nos. mostly reached 3000 plates/20 cm. These monolithic columns exhibited excellent mech. strength as well as thermal stability, and they were properly operated even at a temp. of 80°C and a high linear velocity of 100 mm/s. At 80°C, the theor. plate nos. exceeded 6000 plates/20 cm due to the enhanced mass transfer. Consequently, a series of alkylbenzenes, from toluene to amylbenzene, could be efficiently sepd. within 30 s on the 20 cm-long column by carrying out a ultra-high flow rate gradient at 80°C. [on SciFinder(R)]},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Rapid reversed-phase sepn. in the time-scale of seconds was conducted using methacrylate-based C18 monolithic capillary columns at high flow rates and elevated temps. The reversed-phase monolithic columns were prepd. by in situ polymn. of octadecyl methacrylate (ODMA) and ethylene dimethacrylate (EDMA) within the confines of a polyimide-coated fused silica capillary. When a mixt. of isoamyl alc. and 1,4-butandiol was employed as a porogenic solvent, highly permeable monolithic stationary phases with adequate sepn. efficiency were reproducibly produced. The pressure drops of 20 cm-long columns were typically below 0.4 MPa at a normal flow rate of 3 $mu$L/min (linear velocity of 1 mm/s), and the theor. plate nos. mostly reached 3000 plates/20 cm. These monolithic columns exhibited excellent mech. strength as well as thermal stability, and they were properly operated even at a temp. of 80°C and a high linear velocity of 100 mm/s. At 80°C, the theor. plate nos. exceeded 6000 plates/20 cm due to the enhanced mass transfer. Consequently, a series of alkylbenzenes, from toluene to amylbenzene, could be efficiently sepd. within 30 s on the 20 cm-long column by carrying out a ultra-high flow rate gradient at 80°C. [on SciFinder(R)] |
Tsunoda, Kin-ichi; Shimosakai, Ken-ichi; Hashimoto, Yasuyuki; Umemura, Tomonari; Odake, Tamao. Spectroelectrochemical measurements of iodine with an ITO electrode slab optical waveguide. Journal Article In: Bunseki Kagaku, vol. 54, no. 6, pp. 561–564, 2005, ISSN: 0525-1931. @article{Tsunoda2005,
title = {Spectroelectrochemical measurements of iodine with an ITO electrode slab optical waveguide.},
author = {Tsunoda, Kin-ichi and Shimosakai, Ken-ichi and Hashimoto, Yasuyuki and Umemura, Tomonari and Odake, Tamao.},
doi = {10.2116/bunsekikagaku.54.561},
issn = {0525-1931},
year = {2005},
date = {2005-01-01},
journal = {Bunseki Kagaku},
volume = {54},
number = {6},
pages = {561--564},
publisher = {Nippon Bunseki Kagakkai},
abstract = {An ITO electrode slab optical waveguide spectroelectrochem. measurement system was built for simultaneous Visible attenuated total reflection (ATR) and electrochem. measurements and was applied to study the spectroelectrochem. behavior of I at the ITO electrode. The cyclic voltammogram and the potential-absorbance curve at 430 nm for the redox reaction of I were obsd. and the formation of I was confirmed by the Visible ATR spectra of I ($łambda$max = 430 nm) which showed blue-shift compared with those of gaseous I as well as I in nonpolar solvents ($łambda$max = 500-600 nm). Also, the linear responses of the peak current and the max. absorbance for the oxidn. reaction of iodide were obtained to the concn. of iodide in aq. samples. [on SciFinder(R)]},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
An ITO electrode slab optical waveguide spectroelectrochem. measurement system was built for simultaneous Visible attenuated total reflection (ATR) and electrochem. measurements and was applied to study the spectroelectrochem. behavior of I at the ITO electrode. The cyclic voltammogram and the potential-absorbance curve at 430 nm for the redox reaction of I were obsd. and the formation of I was confirmed by the Visible ATR spectra of I ($łambda$max = 430 nm) which showed blue-shift compared with those of gaseous I as well as I in nonpolar solvents ($łambda$max = 500-600 nm). Also, the linear responses of the peak current and the max. absorbance for the oxidn. reaction of iodide were obtained to the concn. of iodide in aq. samples. [on SciFinder(R)] |
Zhu, Yanbei; Itoh, Akihide; Fujimori, Eiji; Umemura, Tomonari; Haraguchi, Hiroki. Multielement determination of trace metals in seawater by inductively coupled plasma mass spectrometry after tandem preconcentration using a chelating resin. Journal Article In: Bulletin of the Chemical Society of Japan, vol. 78, no. 4, pp. 659–667, 2005, ISSN: 0009-2673. @article{Zhu2005a,
title = {Multielement determination of trace metals in seawater by inductively coupled plasma mass spectrometry after tandem preconcentration using a chelating resin.},
author = {Zhu, Yanbei and Itoh, Akihide and Fujimori, Eiji and Umemura, Tomonari and Haraguchi, Hiroki.},
doi = {10.1246/bcsj.78.659},
issn = {0009-2673},
year = {2005},
date = {2005-01-01},
journal = {Bulletin of the Chemical Society of Japan},
volume = {78},
number = {4},
pages = {659--667},
publisher = {Chemical Society of Japan},
abstract = {A tandem preconcn. method using a chelating resin was exploited for simultaneous multielement detn. of trace metals in seawater by inductively coupled plasma mass spectrometry (ICP-MS). In the 1st preconcn. step. 500 ML of seawater sample was adjusted to pH 6.0, and the adsorption of trace metals on 0.4 g of Chelex-100 resin in dry wt. was carried out at 55°. After equil., the resin was collected on a glass filter and rinsed with 30 mL of ammonium acetate soln. (pH 6.0) to reduce major elements such as Na, K, Mg, and Ca that had been partly adsorbed on the resin. Then, trace metals on the resin were eluted with 7.5 mL of 2 M nitric acid and collected in a 30 mL polypropylene bottle. In the 2nd preconcn. step, the mixt. of the filtrate and the rinsing soln. obtained in the 1st step was adjusted to pH 4.0, and metal adsorption on another 0.4 g of Chelex-100 resin was carried out at 20°. In a similar manner to the 1st step, the resin collected on a glass filter was rinsed with 10 mL of ammonium acetate soln. (pH 4.0), and trace metals adsorbed on the resin were eluted with 6 mL of 2 M nitric acid. This eluate was taken into the same polypropylene bottle as used in the 1st step. The final sample vol. thus obtained was 15 mL including 1.5 mL of internal std. soln. Then a 33-fold preconcn. factor was achieved, where the recoveries for 33 elements were larger than 80%. The anal. results for trace metals in coastal seawater ref. material (CASS-4) were in fairly good agreement with the certified or information values after correction with the recovery values. The coastal seawater samples from the Ise Bay and the Take Island were also analyzed by the present method. The concns. for 20 trace metals in the Ise Bay coastal seawater are >2-fold larger than those in the Take Island coastal seawater, indicating considerable anthropogenic pollution in the Ise Bay area. [on SciFinder(R)]},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
A tandem preconcn. method using a chelating resin was exploited for simultaneous multielement detn. of trace metals in seawater by inductively coupled plasma mass spectrometry (ICP-MS). In the 1st preconcn. step. 500 ML of seawater sample was adjusted to pH 6.0, and the adsorption of trace metals on 0.4 g of Chelex-100 resin in dry wt. was carried out at 55°. After equil., the resin was collected on a glass filter and rinsed with 30 mL of ammonium acetate soln. (pH 6.0) to reduce major elements such as Na, K, Mg, and Ca that had been partly adsorbed on the resin. Then, trace metals on the resin were eluted with 7.5 mL of 2 M nitric acid and collected in a 30 mL polypropylene bottle. In the 2nd preconcn. step, the mixt. of the filtrate and the rinsing soln. obtained in the 1st step was adjusted to pH 4.0, and metal adsorption on another 0.4 g of Chelex-100 resin was carried out at 20°. In a similar manner to the 1st step, the resin collected on a glass filter was rinsed with 10 mL of ammonium acetate soln. (pH 4.0), and trace metals adsorbed on the resin were eluted with 6 mL of 2 M nitric acid. This eluate was taken into the same polypropylene bottle as used in the 1st step. The final sample vol. thus obtained was 15 mL including 1.5 mL of internal std. soln. Then a 33-fold preconcn. factor was achieved, where the recoveries for 33 elements were larger than 80%. The anal. results for trace metals in coastal seawater ref. material (CASS-4) were in fairly good agreement with the certified or information values after correction with the recovery values. The coastal seawater samples from the Ise Bay and the Take Island were also analyzed by the present method. The concns. for 20 trace metals in the Ise Bay coastal seawater are >2-fold larger than those in the Take Island coastal seawater, indicating considerable anthropogenic pollution in the Ise Bay area. [on SciFinder(R)] |
Zhu, Yanbei; Hattori, Ryota; Fujimori, Eiji; Umemura, Tomonari; Haraguchi, Hiroki. Multielement determination of trace metals in river water (certified reference materials, JSAC 0301-1) by high efficiency nebulization ICP-MS after 100-fold preconcentration with a chelating resin-packed minicolumn. Journal Article In: Analytical Sciences, vol. 21, no. 3, pp. 199–203, 2005, ISSN: 0910-6340. @article{Zhu2005b,
title = {Multielement determination of trace metals in river water (certified reference materials, JSAC 0301-1) by high efficiency nebulization ICP-MS after 100-fold preconcentration with a chelating resin-packed minicolumn.},
author = {Zhu, Yanbei and Hattori, Ryota and Fujimori, Eiji and Umemura, Tomonari and Haraguchi, Hiroki.},
doi = {10.2116/analsci.21.199},
issn = {0910-6340},
year = {2005},
date = {2005-01-01},
journal = {Analytical Sciences},
volume = {21},
number = {3},
pages = {199--203},
publisher = {Japan Society for Analytical Chemistry},
abstract = {The detn. of 34 trace metals in a river water certified ref. material (CRM), i.e. JSAC 0301-1, which was issued by the Japan Society for Anal. Chem. in Jan. 2004, was performed by ICP-MS with a high efficiency nebulizer after preconcn. with a lab.-made chelating resin-packed minicolumn, with which trace metals were concd. 100-fold from 50 mL of a river water sample to 0.5 mL of the final anal. soln. Trace metals in JSAC 0301-1 were obsd. in the concn. range from 19 $mu$g L-1 of Al to 0.000053 $mu$g L-1 of Bi. Most of the concns. of trace metals, including rare earth elements (REEs), in JSAC 0301-1 were lower than those in JAC 0031, which was also a previously issued CRM prepd. with H2O from the same river as that of JSAC 0301-1. The low concns. of trace metals in JSAC 0301-1 might be attributed to the fact that there was a heavy rain before collecting the original H2O sample to prep. the present CRM. Also, the REE distribution patterns of JSAC 0301-1, JAC 0031 and the av. values of river water samples in Japan were parallel to each other. The distributions of REEs in JSAC 0301-1 and JAC 0031 were the typical ones of river water samples in Japan. [on SciFinder(R)]},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
The detn. of 34 trace metals in a river water certified ref. material (CRM), i.e. JSAC 0301-1, which was issued by the Japan Society for Anal. Chem. in Jan. 2004, was performed by ICP-MS with a high efficiency nebulizer after preconcn. with a lab.-made chelating resin-packed minicolumn, with which trace metals were concd. 100-fold from 50 mL of a river water sample to 0.5 mL of the final anal. soln. Trace metals in JSAC 0301-1 were obsd. in the concn. range from 19 $mu$g L-1 of Al to 0.000053 $mu$g L-1 of Bi. Most of the concns. of trace metals, including rare earth elements (REEs), in JSAC 0301-1 were lower than those in JAC 0031, which was also a previously issued CRM prepd. with H2O from the same river as that of JSAC 0301-1. The low concns. of trace metals in JSAC 0301-1 might be attributed to the fact that there was a heavy rain before collecting the original H2O sample to prep. the present CRM. Also, the REE distribution patterns of JSAC 0301-1, JAC 0031 and the av. values of river water samples in Japan were parallel to each other. The distributions of REEs in JSAC 0301-1 and JAC 0031 were the typical ones of river water samples in Japan. [on SciFinder(R)] |
Tsunoda, Kin-Ichi; Kasuya, Yuichi; Umemura, Tomonari; Odake, Tamao. A sub-second, time-resolved, linear dichroism measurement system for visible attenuated total reflection spectroscopy with a slab optical waveguide. Journal Article In: Talanta, vol. 65, no. 5, pp. 1097–1101, 2005, ISSN: 0039-9140. @article{Tsunoda2005a,
title = {A sub-second, time-resolved, linear dichroism measurement system for visible attenuated total reflection spectroscopy with a slab optical waveguide.},
author = {Tsunoda, Kin-Ichi and Kasuya, Yuichi and Umemura, Tomonari and Odake, Tamao.},
doi = {10.1016/j.talanta.2004.06.046},
issn = {0039-9140},
year = {2005},
date = {2005-01-01},
journal = {Talanta},
volume = {65},
number = {5},
pages = {1097--1101},
publisher = {Elsevier B.V.},
abstract = {A sub-second, time-resolved, linear dichroism (LD) measurement system was constructed, fitted with a slab optical waveguide (SOWG), and utilized to observe the adsorption process of methylene blue (MB) onto silica surfaces. In the system, a semiconductor laser (670 nm) was used as the light source and the out-coupled beam from the SOWG was split by a polarizing beam splitter into two polarized beams (TE and TM modes) to allow sequential linear dichroic ratio data to be obtained; the acquisition rate was 11 data sets per s. For an MB soln. that contained no sodium dodecylbenzenesulfonate (DBS), in contact with a bare silica surface, a clear decrease occurred in the av. orientation angle of adsorbed MB in the initial stages of the adsorption process. This result may correspond to a change in the chem. form of MB from monomer to dimer. [on SciFinder(R)]},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
A sub-second, time-resolved, linear dichroism (LD) measurement system was constructed, fitted with a slab optical waveguide (SOWG), and utilized to observe the adsorption process of methylene blue (MB) onto silica surfaces. In the system, a semiconductor laser (670 nm) was used as the light source and the out-coupled beam from the SOWG was split by a polarizing beam splitter into two polarized beams (TE and TM modes) to allow sequential linear dichroic ratio data to be obtained; the acquisition rate was 11 data sets per s. For an MB soln. that contained no sodium dodecylbenzenesulfonate (DBS), in contact with a bare silica surface, a clear decrease occurred in the av. orientation angle of adsorbed MB in the initial stages of the adsorption process. This result may correspond to a change in the chem. form of MB from monomer to dimer. [on SciFinder(R)] |
2004 |
Haraguchi, Hiroki; Zhu, Yanbei; Hattori, Ryota; Itoh, Akihide; Umemura, Tomonari. Multielement analysis of commercial mineral waters by chelating resin preconcentration and ICP-MS. Journal Article In: Biomedical Research on Trace Elements, vol. 15, no. 4, pp. 355–357, 2004, ISSN: 0916-717X. @article{Haraguchi2004,
title = {Multielement analysis of commercial mineral waters by chelating resin preconcentration and ICP-MS.},
author = {Haraguchi, Hiroki and Zhu, Yanbei and Hattori, Ryota and Itoh, Akihide and Umemura, Tomonari.},
issn = {0916-717X},
year = {2004},
date = {2004-01-01},
journal = {Biomedical Research on Trace Elements},
volume = {15},
number = {4},
pages = {355--357},
publisher = {Nippon Biryo Genso Gakkai},
abstract = {Trace metals in com.-available 18 mineral waters were detd. by ICP-MS, where a chelating resin-packed minicolumn was applied to sep. matrix elements as well as to preconc. trace metals in the samples. The 25-fold concn. for trace metals was obtained by preconcg. 50 mL of mineral H2O to 2.0 mL of final anal. soln. At the same time, matrix elements were substantially eliminated, so that trace metals could be detd. by ICP-MS on the multielement basis. The validation of the present anal. method was examd. by detg. trace metals in river water ref. material (JAC 0032). Trace metals in tap H2O from Nagoya city were detd. by the present method, and their concns. were compared to those in mineral H2O. [on SciFinder(R)]},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Trace metals in com.-available 18 mineral waters were detd. by ICP-MS, where a chelating resin-packed minicolumn was applied to sep. matrix elements as well as to preconc. trace metals in the samples. The 25-fold concn. for trace metals was obtained by preconcg. 50 mL of mineral H2O to 2.0 mL of final anal. soln. At the same time, matrix elements were substantially eliminated, so that trace metals could be detd. by ICP-MS on the multielement basis. The validation of the present anal. method was examd. by detg. trace metals in river water ref. material (JAC 0032). Trace metals in tap H2O from Nagoya city were detd. by the present method, and their concns. were compared to those in mineral H2O. [on SciFinder(R)] |
Matsuura, Hirotaka; Takatani, Kohei; Sugita, Masaru; Hasegawa, Takuya; Umemura, Tomonari; Haraguchi, Hiroki. Speciation of some biometals in salmon egg cell cytoplasm by two-dimensional HPLC/ICP-MS. Journal Article In: Biomedical Research on Trace Elements, vol. 15, no. 4, pp. 345–347, 2004, ISSN: 0916-717X. @article{Matsuura2004,
title = {Speciation of some biometals in salmon egg cell cytoplasm by two-dimensional HPLC/ICP-MS.},
author = {Matsuura, Hirotaka and Takatani, Kohei and Sugita, Masaru and Hasegawa, Takuya and Umemura, Tomonari and Haraguchi, Hiroki.},
issn = {0916-717X},
year = {2004},
date = {2004-01-01},
journal = {Biomedical Research on Trace Elements},
volume = {15},
number = {4},
pages = {345--347},
publisher = {Nippon Biryo Genso Gakkai},
abstract = {A two-dimensional (2D) HPLC/ICP-MS hyphenated system was developed and applied to speciation of biometals in salmon egg cell cytoplasm. The 2D HPLC was based on the combination of surfactant-mediated HPLC and size exclusion chromatog. (SEC). In the present expt., an ODS column coated with CHAPS (3-[(3-cholamidopropyl) dimethylammonio]-1-propanesulfonate), which is a zwitterionic bile acid deriv., was employed as a sepn. column in the first-dimensional surfactant-mediated HPLC. The surfactant-mediated HPLC allowed simultaneous sepn. of large and small mols. In the second-dimensional HPLC, proteins thus sepd. from inorg. salts in the first dimension were further sepd. by the SEC column. The present 2D HPLC/ICP-MS system was available for the improvement of resoln. in SEC sepn. of metalloproteins in salmon egg cell cytoplasm. Metalloproteins including Fe and Zn in salmon egg cell cytoplasm were detected as only one large peak at the vol. of total exclusion limit of SEC column (>300 kDa), when analyzed by SEC/ICP-MS. However, these metalloproteins could be detected as two peaks in the present 2D HPLC/ICP-MS measurements; the mol. wts. of Fe-proteins were >300 kDa and 100 kDa, and those of Zn-proteins were >300 kDa and 150 kDa. [on SciFinder(R)]},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
A two-dimensional (2D) HPLC/ICP-MS hyphenated system was developed and applied to speciation of biometals in salmon egg cell cytoplasm. The 2D HPLC was based on the combination of surfactant-mediated HPLC and size exclusion chromatog. (SEC). In the present expt., an ODS column coated with CHAPS (3-[(3-cholamidopropyl) dimethylammonio]-1-propanesulfonate), which is a zwitterionic bile acid deriv., was employed as a sepn. column in the first-dimensional surfactant-mediated HPLC. The surfactant-mediated HPLC allowed simultaneous sepn. of large and small mols. In the second-dimensional HPLC, proteins thus sepd. from inorg. salts in the first dimension were further sepd. by the SEC column. The present 2D HPLC/ICP-MS system was available for the improvement of resoln. in SEC sepn. of metalloproteins in salmon egg cell cytoplasm. Metalloproteins including Fe and Zn in salmon egg cell cytoplasm were detected as only one large peak at the vol. of total exclusion limit of SEC column (>300 kDa), when analyzed by SEC/ICP-MS. However, these metalloproteins could be detected as two peaks in the present 2D HPLC/ICP-MS measurements; the mol. wts. of Fe-proteins were >300 kDa and 100 kDa, and those of Zn-proteins were >300 kDa and 150 kDa. [on SciFinder(R)] |
Li, Jinxiang; Ogasawara, Ayaka; Odake, Tamao; Umemura, Tomonari; Tsunoda, Kin-ichi. A new isoelectric focusing system for fast two-dimensional gel electrophoresis using a low-concentration polyacrylamide gel supported by a loose multifilament string. Journal Article In: Analytical Sciences, vol. 20, no. 12, pp. 1673–1679, 2004, ISSN: 0910-6340. @article{Li2004,
title = {A new isoelectric focusing system for fast two-dimensional gel electrophoresis using a low-concentration polyacrylamide gel supported by a loose multifilament string.},
author = {Li, Jinxiang and Ogasawara, Ayaka and Odake, Tamao and Umemura, Tomonari and Tsunoda, Kin-ichi.},
doi = {10.2116/analsci.20.1673},
issn = {0910-6340},
year = {2004},
date = {2004-01-01},
journal = {Analytical Sciences},
volume = {20},
number = {12},
pages = {1673--1679},
publisher = {Japan Society for Analytical Chemistry},
abstract = {A new isoelec. focusing (IEF) system for two-dimensional PAGE (2-D PAGE) has been proposed. In this system, a super-soft and tough IEF gel was achieved by casting polyacrylamide gel down to 2.0% T using a loose multifilament string (LMS) of nylon as a gel support. The IEF app. for the LMS-gel, fabricated from acrylic boards, had a cooling water chamber, and eliminated the need of electrode solns. by directly connecting the two ends of individual gels to platinum electrodes. The carrier ampholyte-generated pH gradients using the new IEF system was stable over a long duration of time and a wide range of voltages, and the IEF time became shorter using a 2.0% T gel than using a 4.0% T gel. Also, the LMS-gels prepd. in different runs exhibited excellent reproducibility. The new IEF system was applied to 2-D PAGE of a chicken skeletal muscle ext., and it was found that the protein loading capacity, protein entry into the LMS-gels, and protein transfer efficiency from the first-dimensional to the second-dimensional gels were significantly improved by using a low-concn. (2.5% T) gel. Also, proteins of high mol. wt. of more than 200 kDa were obsd. in the 2-D maps, and therefore the new IEF system has a very good potential to be applied for fast 2-D PAGE of high mol.-wt. proteins. [on SciFinder(R)]},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
A new isoelec. focusing (IEF) system for two-dimensional PAGE (2-D PAGE) has been proposed. In this system, a super-soft and tough IEF gel was achieved by casting polyacrylamide gel down to 2.0% T using a loose multifilament string (LMS) of nylon as a gel support. The IEF app. for the LMS-gel, fabricated from acrylic boards, had a cooling water chamber, and eliminated the need of electrode solns. by directly connecting the two ends of individual gels to platinum electrodes. The carrier ampholyte-generated pH gradients using the new IEF system was stable over a long duration of time and a wide range of voltages, and the IEF time became shorter using a 2.0% T gel than using a 4.0% T gel. Also, the LMS-gels prepd. in different runs exhibited excellent reproducibility. The new IEF system was applied to 2-D PAGE of a chicken skeletal muscle ext., and it was found that the protein loading capacity, protein entry into the LMS-gels, and protein transfer efficiency from the first-dimensional to the second-dimensional gels were significantly improved by using a low-concn. (2.5% T) gel. Also, proteins of high mol. wt. of more than 200 kDa were obsd. in the 2-D maps, and therefore the new IEF system has a very good potential to be applied for fast 2-D PAGE of high mol.-wt. proteins. [on SciFinder(R)] |
Ueki, Yuji; Umemura, Tomonari; Li, Jinxiang; Odake, Tamao; Tsunoda, Kinichi. Preparation and Application of Methacrylate-Based Cation-Exchange Monolithic Columns for Capillary Ion Chromatography. Journal Article In: Analytical Chemistry, vol. 76, no. 23, pp. 7007–7012, 2004, ISSN: 0003-2700. @article{Ueki2004,
title = {Preparation and Application of Methacrylate-Based Cation-Exchange Monolithic Columns for Capillary Ion Chromatography.},
author = {Ueki, Yuji and Umemura, Tomonari and Li, Jinxiang and Odake, Tamao and Tsunoda, Kinichi.},
doi = {10.1021/ac040079g},
issn = {0003-2700},
year = {2004},
date = {2004-01-01},
journal = {Analytical Chemistry},
volume = {76},
number = {23},
pages = {7007--7012},
publisher = {American Chemical Society},
abstract = {Polymer-based strong cation-exchange monolithic capillary columns with different capacities were constructed for ion chromatog. by radical polymn. of glycidyl methacrylate (GMA) and ethylene dimethacrylate in a 250-$mu$m-i.d. Fused-silica capillary and its subsequent sulfonation based on ring opening of epoxides with 1 M Na2SO3. The cation-exchange capacities can easily and reproducibly be controlled in the range of up to 300 $mu$equiv/mL by changing the immersion time of the epoxy-contg. polymer in the Na2SO3 soln. The chromatog. performance of the produced monolithic capillary columns was evaluated through the sepn. of a model mixt. of common cations such as Na+, NH4+, K+, Mg2+, and Ca2+. As an example, these cations could be well sepd. from one another on a 15-cm-long cation-exchange monolithic column (column vol., 7.4 $mu$L) with a capacity of 150 $mu$equiv/mL by elution with 10 mM CuSO4. The pressure drop of this 15-cm column was ∼1 MPa at a normal linear velocity of 1 mm/s (a flow rate of 3 $mu$L/min), and the nos. of theor. plates for the cations were above 3000 plates/15 cm. This GMA-based cation-exchange monolithic column could withstand high linear velocities of at least 10 mm/s. Over a period of at least two weeks of continuous use, no significant changes in the selectivity and resoln. were obsd. The applicability of a flow rate gradient elution and the feasibility of direct injection detn. of major cations in human saliva sample were also presented. [on SciFinder(R)]},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Polymer-based strong cation-exchange monolithic capillary columns with different capacities were constructed for ion chromatog. by radical polymn. of glycidyl methacrylate (GMA) and ethylene dimethacrylate in a 250-$mu$m-i.d. Fused-silica capillary and its subsequent sulfonation based on ring opening of epoxides with 1 M Na2SO3. The cation-exchange capacities can easily and reproducibly be controlled in the range of up to 300 $mu$equiv/mL by changing the immersion time of the epoxy-contg. polymer in the Na2SO3 soln. The chromatog. performance of the produced monolithic capillary columns was evaluated through the sepn. of a model mixt. of common cations such as Na+, NH4+, K+, Mg2+, and Ca2+. As an example, these cations could be well sepd. from one another on a 15-cm-long cation-exchange monolithic column (column vol., 7.4 $mu$L) with a capacity of 150 $mu$equiv/mL by elution with 10 mM CuSO4. The pressure drop of this 15-cm column was ∼1 MPa at a normal linear velocity of 1 mm/s (a flow rate of 3 $mu$L/min), and the nos. of theor. plates for the cations were above 3000 plates/15 cm. This GMA-based cation-exchange monolithic column could withstand high linear velocities of at least 10 mm/s. Over a period of at least two weeks of continuous use, no significant changes in the selectivity and resoln. were obsd. The applicability of a flow rate gradient elution and the feasibility of direct injection detn. of major cations in human saliva sample were also presented. [on SciFinder(R)] |
Yoshimura, Etsuro; Akashi, Mariko; Umemura, Tomonari; Tsunoda, Kin-ichi. Identification of Al(III) species in a solution containing equimolar concentrations of Al(III) and citric acid using varying-temperature 27Al NMR spectrometry. Journal Article In: Analytical Sciences, vol. 20, no. 2, pp. 373–374, 2004, ISSN: 0910-6340. @article{Yoshimura2004,
title = {Identification of Al(III) species in a solution containing equimolar concentrations of Al(III) and citric acid using varying-temperature 27Al NMR spectrometry.},
author = {Yoshimura, Etsuro and Akashi, Mariko and Umemura, Tomonari and Tsunoda, Kin-ichi.},
doi = {10.2116/analsci.20.373},
issn = {0910-6340},
year = {2004},
date = {2004-01-01},
journal = {Analytical Sciences},
volume = {20},
number = {2},
pages = {373--374},
publisher = {Japan Society for Analytical Chemistry},
abstract = {27Al NMR spectra of an equimolar (10 mM) Al(III)-citrate system were obtained at different temps. The linewidths of the signals decreased in the spectra recorded at elevated temps., which enabled one to unequivocally identify the resonance lines. From the spectrum recorded at 65°, a mononuclear Al(III)-citrate complex was identified at a soln. pH of 3.0 in addn. to trinuclear Al(III)-citrate complex, which dominated at pH 4.0. [on SciFinder(R)]},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
27Al NMR spectra of an equimolar (10 mM) Al(III)-citrate system were obtained at different temps. The linewidths of the signals decreased in the spectra recorded at elevated temps., which enabled one to unequivocally identify the resonance lines. From the spectrum recorded at 65°, a mononuclear Al(III)-citrate complex was identified at a soln. pH of 3.0 in addn. to trinuclear Al(III)-citrate complex, which dominated at pH 4.0. [on SciFinder(R)] |