The separation of enantiomers is of great importance in biology, pharmaceutics, agriculture and environment. The different separation modes (i.e. capillary zone electrophoresis (CZE), micellar electrokinetic chromatog...The separation of enantiomers is of great importance in biology, pharmaceutics, agriculture and environment. The different separation modes (i.e. capillary zone electrophoresis (CZE), micellar electrokinetic chromatography (MEKC), capillary electrochromatography (CEC), etc) and many chiral selectors available make capillary electrophoresis (CE) technique a powerful tool for chiral analysis[1]. On the basis of ligand-exchange (LE) mechanism introduced by Davankov and Rogozhin[2] in the early 1970s for high performance liquid chromatography (HPLC), the first application of CE in chiral separation was reported by Zare's group[3,4]. Using Cu(Ⅱ) complexes of L-histidine or aspartame as chiral selectors, 14 dansyl amino acids (Dns-AAs) were resolved. The authors observed a significant improvement in resolution when a micelle forming surfactant such as sodium dodecyl sulfate (SDS) was added to the electrolyte performing MEKC. The method was called as ligand-exchange micellar electrokinetic capillary chromatography (LE-MEKC). As a hybrid mode of possessing both the advantage of high enantioselectivity in ligand-exchange mechanism and the main advantages of MEKC, LE-MEKC allows the manipulation of the selectivity for large classes of neutral and charged compounds, making possible separation that otherwise are not feasible by using only the mode of LE or MEKC. Using this combined separation mode, hydroxy acids and dipeptides, as well as 16 positional and optical isomers of tryptophan derivatives could be optically resolved[5]. The same group also proposed a method for the determination of the critical micelle concentration (CMC) of anionic surfactants based on LE-MEKC principle[6].展开更多
通过毛细管微乳液电动色谱10 m in内同时分离了安非他明、甲基安非他明、4,5-亚甲基二氧基安非他明(MDA)和3-甲氧基-4,5-亚甲基二氧基安非他明(MDMA)4种苯丙胺类毒品及其麻黄碱、伪麻黄碱、甲基麻黄碱、甲基伪麻黄碱、去甲麻黄碱等麻黄...通过毛细管微乳液电动色谱10 m in内同时分离了安非他明、甲基安非他明、4,5-亚甲基二氧基安非他明(MDA)和3-甲氧基-4,5-亚甲基二氧基安非他明(MDMA)4种苯丙胺类毒品及其麻黄碱、伪麻黄碱、甲基麻黄碱、甲基伪麻黄碱、去甲麻黄碱等麻黄生物碱杂质。比较了毛细管微乳液电动色谱和丁醇改进的胶束电动色谱模式对分离的影响,发现正丁醇是影响分离的最主要因素。本方法具有很好的重复性和稳定性,可实现对冰毒及其麻黄生物碱杂质的快速分析和鉴定,相对保留时间和相对峰面积的RSD分别小于1.3%和5.0%,可用于冰毒的实际来源推断。展开更多
建立了微乳液毛细管电动色谱同时分析消炎利胆片中穿心莲内酯和脱水穿心莲内酯的方法。考察了缓冲溶液的浓度、pH值、十二烷基硫酸钠(SD S)以及助表面活性剂的含量对分离测定的影响。在由乙酸乙酯-SD S-正丁醇-30mm o l/L硼砂缓冲液(pH9...建立了微乳液毛细管电动色谱同时分析消炎利胆片中穿心莲内酯和脱水穿心莲内酯的方法。考察了缓冲溶液的浓度、pH值、十二烷基硫酸钠(SD S)以及助表面活性剂的含量对分离测定的影响。在由乙酸乙酯-SD S-正丁醇-30mm o l/L硼砂缓冲液(pH9.5)(质量比为0.5∶0.6∶6.0∶92.9)组成的微乳液体系中,两种内酯在6m in内完成分离。该法简便、快速、选择性好,用于实际样品中穿心莲内酯和脱水穿心莲内酯的分析,获得了满意的结果。展开更多
文摘The separation of enantiomers is of great importance in biology, pharmaceutics, agriculture and environment. The different separation modes (i.e. capillary zone electrophoresis (CZE), micellar electrokinetic chromatography (MEKC), capillary electrochromatography (CEC), etc) and many chiral selectors available make capillary electrophoresis (CE) technique a powerful tool for chiral analysis[1]. On the basis of ligand-exchange (LE) mechanism introduced by Davankov and Rogozhin[2] in the early 1970s for high performance liquid chromatography (HPLC), the first application of CE in chiral separation was reported by Zare's group[3,4]. Using Cu(Ⅱ) complexes of L-histidine or aspartame as chiral selectors, 14 dansyl amino acids (Dns-AAs) were resolved. The authors observed a significant improvement in resolution when a micelle forming surfactant such as sodium dodecyl sulfate (SDS) was added to the electrolyte performing MEKC. The method was called as ligand-exchange micellar electrokinetic capillary chromatography (LE-MEKC). As a hybrid mode of possessing both the advantage of high enantioselectivity in ligand-exchange mechanism and the main advantages of MEKC, LE-MEKC allows the manipulation of the selectivity for large classes of neutral and charged compounds, making possible separation that otherwise are not feasible by using only the mode of LE or MEKC. Using this combined separation mode, hydroxy acids and dipeptides, as well as 16 positional and optical isomers of tryptophan derivatives could be optically resolved[5]. The same group also proposed a method for the determination of the critical micelle concentration (CMC) of anionic surfactants based on LE-MEKC principle[6].
文摘通过毛细管微乳液电动色谱10 m in内同时分离了安非他明、甲基安非他明、4,5-亚甲基二氧基安非他明(MDA)和3-甲氧基-4,5-亚甲基二氧基安非他明(MDMA)4种苯丙胺类毒品及其麻黄碱、伪麻黄碱、甲基麻黄碱、甲基伪麻黄碱、去甲麻黄碱等麻黄生物碱杂质。比较了毛细管微乳液电动色谱和丁醇改进的胶束电动色谱模式对分离的影响,发现正丁醇是影响分离的最主要因素。本方法具有很好的重复性和稳定性,可实现对冰毒及其麻黄生物碱杂质的快速分析和鉴定,相对保留时间和相对峰面积的RSD分别小于1.3%和5.0%,可用于冰毒的实际来源推断。
