The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform
Yasuyuki Ishida - One of the best experts on this subject based on the ideXlab platform.
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validation of thermally assisted hydrolysis and methylation gas chromatography using a vertical microfurnace pyrolyzer for the compositional analysis of fatty acid components in microalgae
Journal of Agricultural and Food Chemistry, 2012Co-Authors: Yasuyuki Ishida, Takayuki Honda, Shigemi Mabuchi, Osamu SuenoAbstract:Thermally assisted hydrolysis and methylation–gas chromatography (THM-GC) in the presence of Trimethylsulfonium hydroxide, using a vertical microfurnace pyrolyzer, was validated for the compositional analysis of fatty acid components in microalgae. The chromatograms of a microalga, Pavlova lutheri, obtained under optimized THM conditions clearly showed a series of fatty acid methyl esters including thermally labile polyunsaturated fatty acid components. On the basis of these peak areas, their chemical compositions were rapidly determined without using any tedious sample pretreatment with a precision of <8% relative standard deviation. Moreover, the compositions thus obtained were in good agreement with those obtained by the conventional technique involving solvent extraction. Finally, the THM-GC technique was applied for the compositional analysis of fatty acid components in a newly found microalga, Coccomyxa gloeobotrydiformis. The obtained data showed a high abundance (24 mol %) of α-linolenic acid comp...
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highly sensitive determination of lipid components including polyunsaturated fatty acids in individual zooplankters by one step thermally assisted hydrolysis and methylation gas chromatography in the presence of Trimethylsulfonium hydroxide
Journal of Analytical and Applied Pyrolysis, 2003Co-Authors: Oh Nakanishi, Yasuyuki Ishida, Hajime Ohtani, Shin Tsuge, Shingo Hirao, Jotaro Urabe, Tatsuki Sekino, Masami Nakanishi, Takashi KimotoAbstract:Abstract Thermally assisted hydrolysis and methylation-gas chromatography (THM-GC) in the presence of Trimethylsulfonium hydroxide (TMSH) was applied to the analysis of the lipid contents and their fatty acid compositions in individual zooplankters, especially focusing on polyunsaturated fatty acid (PUFA) components. On the resulting chromatograms, fatty acid components including PUFAs such as eicosapentaenoic acid (EPA; C20:5) and docosahexaenoic acid (DHA; C22:6) in single zooplankters were clearly observed as their methyl esters without doing any tedious and time-consuming pretreatment. By using this technique, the lipid contents and fatty acid compositions in a powdered plankter sample prepared by cryomilling homogenization were estimated on the basis of the observed peak intensities with relative standard deviations of less than 6%. The fatty acid compositions thus determined were in good agreement with those obtained by the conventional technique involving solvent extraction of the samples for every fatty acid component including PUFAs. The differences among individual zooplankter samples were then evaluated by THM-GC method. As a result, the chemical compositions of EPA and DHA showed relatively large inter-individual fluctuations even for the samples cultured under the same conditions. This suggests that lipid biosynthesis of the highly unsaturated fatty acid components and their consumption proceeded differently depending on the life history for each individual zooplankter.
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compositional analysis of polyunsaturated fatty acid oil by one step thermally assisted hydrolysis and methylation in the presence of Trimethylsulfonium hydroxide
Journal of Analytical and Applied Pyrolysis, 1999Co-Authors: Yasuyuki Ishida, S Wakamatsu, Hiroaki Yokoi, Hajime Ohtani, Shin TsugeAbstract:Abstract Thermally assisted hydrolysis and methylation-gas chromatography (THM-GC) in the presence of Trimethylsulfonium hydroxide (TMSH) was applied to the determination of fatty acid composition of lipids containing polyunsaturated fatty acid residues. By using this method, the polyunsaturated fatty acid (PUFA) components as well as saturated and monounsaturated fatty acid residues were observed almost quantitatively as their methyl esters on the resulting chromatogram without causing any appreciable isomerization and/or degradation. On the basis of these peak intensities, the fatty acid compositions in soybean oil and sardine oil samples were rapidly and precisely estimated with less than 6% of the relative standard deviations even for PUFA components such as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA).
Shin Tsuge - One of the best experts on this subject based on the ideXlab platform.
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highly sensitive determination of lipid components including polyunsaturated fatty acids in individual zooplankters by one step thermally assisted hydrolysis and methylation gas chromatography in the presence of Trimethylsulfonium hydroxide
Journal of Analytical and Applied Pyrolysis, 2003Co-Authors: Oh Nakanishi, Yasuyuki Ishida, Hajime Ohtani, Shin Tsuge, Shingo Hirao, Jotaro Urabe, Tatsuki Sekino, Masami Nakanishi, Takashi KimotoAbstract:Abstract Thermally assisted hydrolysis and methylation-gas chromatography (THM-GC) in the presence of Trimethylsulfonium hydroxide (TMSH) was applied to the analysis of the lipid contents and their fatty acid compositions in individual zooplankters, especially focusing on polyunsaturated fatty acid (PUFA) components. On the resulting chromatograms, fatty acid components including PUFAs such as eicosapentaenoic acid (EPA; C20:5) and docosahexaenoic acid (DHA; C22:6) in single zooplankters were clearly observed as their methyl esters without doing any tedious and time-consuming pretreatment. By using this technique, the lipid contents and fatty acid compositions in a powdered plankter sample prepared by cryomilling homogenization were estimated on the basis of the observed peak intensities with relative standard deviations of less than 6%. The fatty acid compositions thus determined were in good agreement with those obtained by the conventional technique involving solvent extraction of the samples for every fatty acid component including PUFAs. The differences among individual zooplankter samples were then evaluated by THM-GC method. As a result, the chemical compositions of EPA and DHA showed relatively large inter-individual fluctuations even for the samples cultured under the same conditions. This suggests that lipid biosynthesis of the highly unsaturated fatty acid components and their consumption proceeded differently depending on the life history for each individual zooplankter.
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compositional analysis of polyunsaturated fatty acid oil by one step thermally assisted hydrolysis and methylation in the presence of Trimethylsulfonium hydroxide
Journal of Analytical and Applied Pyrolysis, 1999Co-Authors: Yasuyuki Ishida, S Wakamatsu, Hiroaki Yokoi, Hajime Ohtani, Shin TsugeAbstract:Abstract Thermally assisted hydrolysis and methylation-gas chromatography (THM-GC) in the presence of Trimethylsulfonium hydroxide (TMSH) was applied to the determination of fatty acid composition of lipids containing polyunsaturated fatty acid residues. By using this method, the polyunsaturated fatty acid (PUFA) components as well as saturated and monounsaturated fatty acid residues were observed almost quantitatively as their methyl esters on the resulting chromatogram without causing any appreciable isomerization and/or degradation. On the basis of these peak intensities, the fatty acid compositions in soybean oil and sardine oil samples were rapidly and precisely estimated with less than 6% of the relative standard deviations even for PUFA components such as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA).
Aron Walsh - One of the best experts on this subject based on the ideXlab platform.
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Trimethylsulfonium lead triiodide an air stable hybrid halide perovskite
Inorganic Chemistry, 2017Co-Authors: Andreas Kaltzoglou, Constantinos C Stoumpos, Athanassios G Kontos, Georgios K Manolis, Kyriakos Papadopoulos, Kyriaki G Papadokostaki, Vasilis Psycharis, Chiu C Tang, Young Kwang Jung, Aron WalshAbstract:We report on the synthesis, characterization, and optoelectronic properties of the novel Trimethylsulfonium lead triiodide perovskite, (CH3)3SPbI3. At room temperature, the air-stable compound adopts a hexagonal crystal structure with a 1D network of face-sharing [PbI6] octahedra along the c axis. UV–vis reflectance spectroscopy on a pressed pellet revealed a band gap of 3.1 eV, in agreement with first-principles calculations, which show a small separation between direct and indirect band gaps. Electrical resistivity measurements on single crystals indicated that the compound behaves as a semiconductor. According to multi-temperature single-crystal X-ray diffraction, synchrotron powder X-ray diffraction, Raman spectroscopy, and differential scanning calorimetry, two fully reversible structural phase transitions occur at −5 and ca. −100 °C with reduction of the unit cell symmetry to monoclinic as temperature decreases. The role of the Trimethylsulfonium cation regarding the chemical stability and optoelect...
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Trimethylsulfonium Lead Triiodide: An Air-Stable Hybrid Halide Perovskite
2017Co-Authors: Andreas Kaltzoglou, Constantinos C Stoumpos, Athanassios G Kontos, Georgios K Manolis, Kyriakos Papadopoulos, Kyriaki G Papadokostaki, Vasilis Psycharis, Chiu C Tang, Young Kwang Jung, Aron WalshAbstract:We report on the synthesis, characterization, and optoelectronic properties of the novel Trimethylsulfonium lead triiodide perovskite, (CH3)3SPbI3. At room temperature, the air-stable compound adopts a hexagonal crystal structure with a 1D network of face-sharing [PbI6] octahedra along the c axis. UV–vis reflectance spectroscopy on a pressed pellet revealed a band gap of 3.1 eV, in agreement with first-principles calculations, which show a small separation between direct and indirect band gaps. Electrical resistivity measurements on single crystals indicated that the compound behaves as a semiconductor. According to multi-temperature single-crystal X-ray diffraction, synchrotron powder X-ray diffraction, Raman spectroscopy, and differential scanning calorimetry, two fully reversible structural phase transitions occur at −5 and ca. −100 °C with reduction of the unit cell symmetry to monoclinic as temperature decreases. The role of the Trimethylsulfonium cation regarding the chemical stability and optoelectronic properties of the new compound is discussed in comparison with APbI3 (A = Cs, methylammonium, and formamidinium cation), which are most commonly used in perovskite solar cells
Peter Wasserscheid - One of the best experts on this subject based on the ideXlab platform.
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aggregation models of potential cyclical Trimethylsulfonium dicyanamide ionic liquid clusters
Journal of Physical Chemistry B, 2009Co-Authors: Robert W Carper, Kevin Langenwalter, Naveed S Nooruddin, Michael J Kullman, Dirk Gerhard, Peter WasserscheidAbstract:Raman and infrared spectra of Trimethylsulfonium dicyanamide [(CH3)3SN(CN)2] are reported and accurately reproduced by DFT methods (B3LYP and B3PW91), MP2, and MP3, and to a lesser extent by the RHF method. The (CH3)3SN(CN)2 ionic liquid forms two isomeric dimers that are of cyclic structure, one of which is 13 kcal/mol lower in energy than the other. Both isomeric cyclic pairs (versions 1 and 2), [(CH3)3SN(CN)2]2, have the potential to further combine and form a common structure containing four pairs of (CH3)3SN(CN)2. This structure can then conceivably undergo a stacking procedure to form extended ionic liquid nanotubes of eight ionic liquids, [(CH3)3SN(CN)2]8. The possible formation of gas phase ionic liquid clusters of two, four, and eight Trimethylsulfonium dicyanamide ionic liquids is supported by highly exergonic free energy changes obtained from B3LYP/(6-311+G(d,p)) density functional calculations.
Hajime Ohtani - One of the best experts on this subject based on the ideXlab platform.
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highly sensitive determination of lipid components including polyunsaturated fatty acids in individual zooplankters by one step thermally assisted hydrolysis and methylation gas chromatography in the presence of Trimethylsulfonium hydroxide
Journal of Analytical and Applied Pyrolysis, 2003Co-Authors: Oh Nakanishi, Yasuyuki Ishida, Hajime Ohtani, Shin Tsuge, Shingo Hirao, Jotaro Urabe, Tatsuki Sekino, Masami Nakanishi, Takashi KimotoAbstract:Abstract Thermally assisted hydrolysis and methylation-gas chromatography (THM-GC) in the presence of Trimethylsulfonium hydroxide (TMSH) was applied to the analysis of the lipid contents and their fatty acid compositions in individual zooplankters, especially focusing on polyunsaturated fatty acid (PUFA) components. On the resulting chromatograms, fatty acid components including PUFAs such as eicosapentaenoic acid (EPA; C20:5) and docosahexaenoic acid (DHA; C22:6) in single zooplankters were clearly observed as their methyl esters without doing any tedious and time-consuming pretreatment. By using this technique, the lipid contents and fatty acid compositions in a powdered plankter sample prepared by cryomilling homogenization were estimated on the basis of the observed peak intensities with relative standard deviations of less than 6%. The fatty acid compositions thus determined were in good agreement with those obtained by the conventional technique involving solvent extraction of the samples for every fatty acid component including PUFAs. The differences among individual zooplankter samples were then evaluated by THM-GC method. As a result, the chemical compositions of EPA and DHA showed relatively large inter-individual fluctuations even for the samples cultured under the same conditions. This suggests that lipid biosynthesis of the highly unsaturated fatty acid components and their consumption proceeded differently depending on the life history for each individual zooplankter.
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compositional analysis of polyunsaturated fatty acid oil by one step thermally assisted hydrolysis and methylation in the presence of Trimethylsulfonium hydroxide
Journal of Analytical and Applied Pyrolysis, 1999Co-Authors: Yasuyuki Ishida, S Wakamatsu, Hiroaki Yokoi, Hajime Ohtani, Shin TsugeAbstract:Abstract Thermally assisted hydrolysis and methylation-gas chromatography (THM-GC) in the presence of Trimethylsulfonium hydroxide (TMSH) was applied to the determination of fatty acid composition of lipids containing polyunsaturated fatty acid residues. By using this method, the polyunsaturated fatty acid (PUFA) components as well as saturated and monounsaturated fatty acid residues were observed almost quantitatively as their methyl esters on the resulting chromatogram without causing any appreciable isomerization and/or degradation. On the basis of these peak intensities, the fatty acid compositions in soybean oil and sardine oil samples were rapidly and precisely estimated with less than 6% of the relative standard deviations even for PUFA components such as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA).
