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Mai Otsuka - One of the best experts on this subject based on the ideXlab platform.
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analysis of nitrogen mustard degradation products via post pentafluorobenzoylation liquid chromatography tandem mass spectrometry
Journal of Chromatography A, 2020Co-Authors: Mai Otsuka, Hajime Miyaguchi, Masanobu UchiyamaAbstract:A pentafluorobenzoylation (PFBz)-liquid chromatography-tandem mass spectrometry method was developed for qualitative and quantitative analysis of ethanolamines (EAs, nitrogen mustard degradation products). With this method, highly hydrophilic EAs can be sufficiently analyzed with a commonly used reversed phase column (retention times: (PFBz)2-methyl Diethanolamine, 9.1 min; (PFBz)2-ethyl Diethanolamine, 9.8 min; and (PFBz)3-triethanolamine, 17.6 min). The applicability of the method for real samples was investigated via recovery tests. Methyl Diethanolamine and ethyl Diethanolamine were detected at concentrations as low as 1 ng/mL in serum and 10 ng/mL in urine, and quantified within the range of 1-1000 ng/mL and 10-1000 ng/mL, respectively.
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analysis of degradation products of nitrogen mustards via hydrophilic interaction liquid chromatography tandem mass spectrometry
Journal of Chromatography A, 2019Co-Authors: Mai Otsuka, Hajime Miyaguchi, Masanobu UchiyamaAbstract:Abstract A hydrophilic interaction liquid chromatography-tandem mass spectrometry (HILIC-MS/MS) method was developed for qualitative and quantitative analysis of ethanolamines (EAs), which are nitrogen mustard degradation products. With this method, the retention times of the highly hydrophilic EAs on the HILIC column were sufficient (retention times: methyl Diethanolamine, 12.2 min; ethyl Diethanolamine, 11.2 min; and triethanolamine, 9.5 min) and the EAs were analyzed more efficiently than with reported HILIC-MS/MS methods. The detection limits of methyl Diethanolamine and ethyl Diethanolamine in serum and urine using this approach were 15–20 ng/mL. The suitability of the method for real samples was evaluated via recovery tests involving urine and serum, and the method was validated. The MS/MS fragmentation of EAs was discussed based on density functional theory calculations.
Calum J Drummond - One of the best experts on this subject based on the ideXlab platform.
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nonionic diethanolamide amphiphiles with saturated hydrocarbon chains neat crystalline and lyotropic liquid crystalline phase behavior
Joint International Conference on Information Sciences, 2012Co-Authors: Sharon M Sagnella, Charlotte E Conn, Irena Krodkiewska, Calum J DrummondAbstract:The solid state and lyotropic phase behavior of a series of nonionic diethanolamide amphiphiles with increasing saturated hydrocarbon chain length (lauroyl, myristoyl, palmitoyl, and stearoyl) has been examined. All four saturated diethanolamide amphiphiles form a crystalline solid with two or three different polymorphic crystalline forms at room temperature. Melting points and associated enthalpies for these four amphiphiles increased with increasing chain length. Approximate partial binary phase diagrams have been constructed for each amphiphile/water system by combining Cross-Polarized Optical Microscopy (POM) and Small-Angle X-ray Scattering (SAXS) results. In the presence of water, all four diethanolamides form an L(α) phase, between 10% and 50% water content, and an L(2) phase with decreasing hydration and increasing temperature. In addition to the L(α) and L(2) phases, the shorter chain diethanolamide amphiphiles (lauroyl and myristoyl) also display a normal micellar phase (L(1)) at higher water contents, occurring to lower temperatures than the L(α) phase. By examining the effect of subtle molecular changes on both neat and lyotropic phase behavior, amphiphiles can be designed with properties tailored to a desired application.
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nonionic diethanolamide amphiphiles with isoprenoid type hydrocarbon chains thermotropic and lyotropic liquid crystalline phase behaviour
Physical Chemistry Chemical Physics, 2011Co-Authors: Sharon M Sagnella, Charlotte E Conn, Irena Krodkiewska, Calum J DrummondAbstract:The thermotropic and lyotropic liquid crystalline phase behaviour of a series of diethanolamide amphiphiles with isoprenoid-type hydrocarbon chains (geranoyl, H-farnesoyl, and phytanoyl) has been investigated. When neat, both H-farnesoyl and phytanoyl diethanolamide form a smectic liquid crystalline structure at sub-zero temperatures. In addition, all three diethanolamides exhibit a glass transition temperature at around -73 °C. Geranoyl diethanolamide forms a lamellar crystalline phase with a lattice parameter of 17.4 A following long term storage accompanied by the loss of the glass transition. In the presence of water, H-farnesoyl and phytanoyl diethanolamide form lyotropic liquid crystalline phases, whilst geranoyl diethanolamide forms an L(2) phase. H-farnesoyl diethanolamide forms a fluid lamellar phase (L(α)) at room temperature and up to ∼ 40 °C. Phytanoyl diethanolamide displays a rich mesomorphism forming the inverse diamond (Q(II)(D)) and gyroid (Q(II)(G)) bicontinuous cubic phases in addition to an L(α) phase.
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nonionic diethanolamide amphiphiles with unsaturated c18 hydrocarbon chains thermotropic and lyotropic liquid crystalline phase behavior
Physical Chemistry Chemical Physics, 2011Co-Authors: Sharon M Sagnella, Charlotte E Conn, Irena Krodkiewska, Calum J DrummondAbstract:The neat and lyotropic liquid crystalline phase behavior of three nonionic diethanolamide amphiphiles with C18 hydrocarbon chains containing one, two or three unsaturated bonds has been examined. This has allowed the effect of degree of unsaturation on the phase behavior of diethanolamide amphiphiles to be investigated. Neat linoleoyl and linolenoyl diethanolamide undergo a transition from a glassy liquid crystal to a liquid crystal at ∼−85 °C, while neat oleoyl diethanolamide undergoes a transition at ∼−60 °C to a liquid crystalline material before re-crystallizing at −34 °C. Oleoyl diethanolamide then undergoes a third transition from a crystalline phase to a smectic liquid crystalline phase at ∼5 °C. In the absence of water, the transition temperature from a smectic liquid crystal to an isotropic liquid decreases with increasing unsaturation. The addition of water results in the formation of a lamellar phase (Lα) for all three amphiphiles. The lamellar phase is stable under excess water conditions up to temperatures of at least 70 °C. Approximate partial binary amphiphile-water phase diagrams generated for the three unsaturated C18 amphiphiles indicate that the excess water point for each amphiphile occurs at ∼60% (w/w) amphiphile.
Masanobu Uchiyama - One of the best experts on this subject based on the ideXlab platform.
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analysis of nitrogen mustard degradation products via post pentafluorobenzoylation liquid chromatography tandem mass spectrometry
Journal of Chromatography A, 2020Co-Authors: Mai Otsuka, Hajime Miyaguchi, Masanobu UchiyamaAbstract:A pentafluorobenzoylation (PFBz)-liquid chromatography-tandem mass spectrometry method was developed for qualitative and quantitative analysis of ethanolamines (EAs, nitrogen mustard degradation products). With this method, highly hydrophilic EAs can be sufficiently analyzed with a commonly used reversed phase column (retention times: (PFBz)2-methyl Diethanolamine, 9.1 min; (PFBz)2-ethyl Diethanolamine, 9.8 min; and (PFBz)3-triethanolamine, 17.6 min). The applicability of the method for real samples was investigated via recovery tests. Methyl Diethanolamine and ethyl Diethanolamine were detected at concentrations as low as 1 ng/mL in serum and 10 ng/mL in urine, and quantified within the range of 1-1000 ng/mL and 10-1000 ng/mL, respectively.
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analysis of degradation products of nitrogen mustards via hydrophilic interaction liquid chromatography tandem mass spectrometry
Journal of Chromatography A, 2019Co-Authors: Mai Otsuka, Hajime Miyaguchi, Masanobu UchiyamaAbstract:Abstract A hydrophilic interaction liquid chromatography-tandem mass spectrometry (HILIC-MS/MS) method was developed for qualitative and quantitative analysis of ethanolamines (EAs), which are nitrogen mustard degradation products. With this method, the retention times of the highly hydrophilic EAs on the HILIC column were sufficient (retention times: methyl Diethanolamine, 12.2 min; ethyl Diethanolamine, 11.2 min; and triethanolamine, 9.5 min) and the EAs were analyzed more efficiently than with reported HILIC-MS/MS methods. The detection limits of methyl Diethanolamine and ethyl Diethanolamine in serum and urine using this approach were 15–20 ng/mL. The suitability of the method for real samples was evaluated via recovery tests involving urine and serum, and the method was validated. The MS/MS fragmentation of EAs was discussed based on density functional theory calculations.
Sharon M Sagnella - One of the best experts on this subject based on the ideXlab platform.
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nonionic diethanolamide amphiphiles with saturated hydrocarbon chains neat crystalline and lyotropic liquid crystalline phase behavior
Joint International Conference on Information Sciences, 2012Co-Authors: Sharon M Sagnella, Charlotte E Conn, Irena Krodkiewska, Calum J DrummondAbstract:The solid state and lyotropic phase behavior of a series of nonionic diethanolamide amphiphiles with increasing saturated hydrocarbon chain length (lauroyl, myristoyl, palmitoyl, and stearoyl) has been examined. All four saturated diethanolamide amphiphiles form a crystalline solid with two or three different polymorphic crystalline forms at room temperature. Melting points and associated enthalpies for these four amphiphiles increased with increasing chain length. Approximate partial binary phase diagrams have been constructed for each amphiphile/water system by combining Cross-Polarized Optical Microscopy (POM) and Small-Angle X-ray Scattering (SAXS) results. In the presence of water, all four diethanolamides form an L(α) phase, between 10% and 50% water content, and an L(2) phase with decreasing hydration and increasing temperature. In addition to the L(α) and L(2) phases, the shorter chain diethanolamide amphiphiles (lauroyl and myristoyl) also display a normal micellar phase (L(1)) at higher water contents, occurring to lower temperatures than the L(α) phase. By examining the effect of subtle molecular changes on both neat and lyotropic phase behavior, amphiphiles can be designed with properties tailored to a desired application.
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nonionic diethanolamide amphiphiles with isoprenoid type hydrocarbon chains thermotropic and lyotropic liquid crystalline phase behaviour
Physical Chemistry Chemical Physics, 2011Co-Authors: Sharon M Sagnella, Charlotte E Conn, Irena Krodkiewska, Calum J DrummondAbstract:The thermotropic and lyotropic liquid crystalline phase behaviour of a series of diethanolamide amphiphiles with isoprenoid-type hydrocarbon chains (geranoyl, H-farnesoyl, and phytanoyl) has been investigated. When neat, both H-farnesoyl and phytanoyl diethanolamide form a smectic liquid crystalline structure at sub-zero temperatures. In addition, all three diethanolamides exhibit a glass transition temperature at around -73 °C. Geranoyl diethanolamide forms a lamellar crystalline phase with a lattice parameter of 17.4 A following long term storage accompanied by the loss of the glass transition. In the presence of water, H-farnesoyl and phytanoyl diethanolamide form lyotropic liquid crystalline phases, whilst geranoyl diethanolamide forms an L(2) phase. H-farnesoyl diethanolamide forms a fluid lamellar phase (L(α)) at room temperature and up to ∼ 40 °C. Phytanoyl diethanolamide displays a rich mesomorphism forming the inverse diamond (Q(II)(D)) and gyroid (Q(II)(G)) bicontinuous cubic phases in addition to an L(α) phase.
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nonionic diethanolamide amphiphiles with unsaturated c18 hydrocarbon chains thermotropic and lyotropic liquid crystalline phase behavior
Physical Chemistry Chemical Physics, 2011Co-Authors: Sharon M Sagnella, Charlotte E Conn, Irena Krodkiewska, Calum J DrummondAbstract:The neat and lyotropic liquid crystalline phase behavior of three nonionic diethanolamide amphiphiles with C18 hydrocarbon chains containing one, two or three unsaturated bonds has been examined. This has allowed the effect of degree of unsaturation on the phase behavior of diethanolamide amphiphiles to be investigated. Neat linoleoyl and linolenoyl diethanolamide undergo a transition from a glassy liquid crystal to a liquid crystal at ∼−85 °C, while neat oleoyl diethanolamide undergoes a transition at ∼−60 °C to a liquid crystalline material before re-crystallizing at −34 °C. Oleoyl diethanolamide then undergoes a third transition from a crystalline phase to a smectic liquid crystalline phase at ∼5 °C. In the absence of water, the transition temperature from a smectic liquid crystal to an isotropic liquid decreases with increasing unsaturation. The addition of water results in the formation of a lamellar phase (Lα) for all three amphiphiles. The lamellar phase is stable under excess water conditions up to temperatures of at least 70 °C. Approximate partial binary amphiphile-water phase diagrams generated for the three unsaturated C18 amphiphiles indicate that the excess water point for each amphiphile occurs at ∼60% (w/w) amphiphile.
Madhusree Kundu - One of the best experts on this subject based on the ideXlab platform.
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solubility of co2 in aqueous blends of Diethanolamine 2 amino 2 methyl 1 propanol and Diethanolamine n methylDiethanolamine
Journal of Chemical & Engineering Data, 2012Co-Authors: G Kumar, Tarun K Mondal, Madhusree KunduAbstract:This work presents experimental data for the CO2 solubility in aqueous blends of Diethanolamine (DEA) + 2-amino-2-methyl-1-propanol (AMP) and Diethanolamine (DEA) + N-methylDiethanolamine (MDEA) at temperatures of (303.1, 313.1, and 323.1) K and CO2 pressure in the range of (1 to 350) kPa. Aqueous ternary mixtures of (DEA + AMP) and (DEA + MDEA) with the following compositions (0.06 mass fraction/0.571 mol·L–1 DEA + 0.24 mass fraction/2.692 mol·L–1 AMP), (0.09 mass fraction/0.856 mol·L–1 DEA + 0.21 mass fraction/2.356 mol·L–1 AMP), (0.12 mass fraction/1.141 mol·L–1 DEA + 0.18 mass fraction/2.019 mol·L–1 AMP), and (0.15 mass fraction/1.427 mol·L–1 DEA + 0.15 mass fraction/1.683 mol·L–1 AMP) and (0.06 mass fraction/0.571 mol·L–1 DEA + 0.24 mass fraction/2.014 mol·L–1 MDEA), (0.09 mass fraction/0.856 mol·L–1 DEA + 0.21 mass fraction/1.762 mol·L–1 MDEA), (0.12 mass fraction/1.141 mol·L–1 DEA + 0.18 mass fraction/1.511 mol·L–1 MDEA), and (0.15 mass fraction/1.427 mol·L–1 DEA + 0.15 mass fraction/1.259 mol·L–1 ...
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physical solubility and diffusivity of n2o and co2 into aqueous solutions of 2 amino 2 methyl 1 propanol monoethanolamine and n methylDiethanolamine monoethanolamine
Journal of Chemical & Engineering Data, 2004Co-Authors: Bishnu P Mandal, Madhusree Kundu, And Nitin U Padhiyar, Syamalendu S BandyopadhyayAbstract:In this work the physical solubility of N2O in (Diethanolamine + water), (2-amino-2-methyl-1-propanol + water), (N-methylDiethanolamine + water), (N-methylDiethanolamine + Diethanolamine + water), and (2-amino-2-methyl-1-propanol + Diethanolamine + water) as well as the diffusivity of N2O in (N-methylDiethanolamine + Diethanolamine + water) and (2-amino-2-methyl-1-propanol + Diethanolamine + water) have been measured at (293, 298, 303, 308, and 313) K. For the binary mixtures the amine concentration ranges studied are (2.0, 2.5, and 3.0) kmol·m-3. For the ternary mixtures the total amine strength in the solution was kept at 30 mass %, in view of the recent interest in using concentrated amine solutions in gas treating. A solubility apparatus was used to measure the solubility of N2O in amine solutions. The diffusivity was measured with a wetted wall column absorber. The uncertainty of the measurement is estimated to be ±2%. A semiempirical model of the excess Henry's constant proposed by Wang et al. (Chem...