A novel micelle to solvent stacking on-line sample preconcentration technique in capillary zone electrophoresis（MSS-CZE） has been developed to determine the strychnine and brucine in traditional Chinese medicine pre...A novel micelle to solvent stacking on-line sample preconcentration technique in capillary zone electrophoresis（MSS-CZE） has been developed to determine the strychnine and brucine in traditional Chinese medicine preparations.The optimal running buffer was 30 mmol/L H_3PO_4 containing 20%acetonitrile at pH 4.0.The sample matrix was 8 mmol/L H_3PO_4 containing 5 mmol/L sodium dodecyl sulfate（SDS） at pH 3.0.The established MSS-CZE method afforded more than 50-fold improvements in concentration sensitivity compared with typical CZE-UV analysis.The calibration curve was linear in the range from 0.2 to 15.0μg/ mL for both strychnine and brucine,with correlation coefficients of 0.9984 and 0.9976,respectively.The limits of detection（5/ N = 3：1） for strychnine and brucine were 0.02 and 0.05μg/mL,respectively.The MSS-CZE method has been successfully applied to the analysis of strychnine and brucine in Chinese medicinal preparations.展开更多
A sample enrichment method focusing on the minor targeted components was established to help them to be successfully separated by pH-zone refining CCC.Seven minor indole alkaloids in Uncaria rhynchophylla(Miq.)Miq.ex ...A sample enrichment method focusing on the minor targeted components was established to help them to be successfully separated by pH-zone refining CCC.Seven minor indole alkaloids in Uncaria rhynchophylla(Miq.)Miq.ex Havil(UR)were chosen to show the advantage of this method.The sample enrichment and separation were展开更多
Zone electrophoresis is suggested with flat capillary instead of circular ones to get over the disadvantages of both the narrow-bore and wlde-bore circular tubes (CT). This method was fully investigated in theory. A f...Zone electrophoresis is suggested with flat capillary instead of circular ones to get over the disadvantages of both the narrow-bore and wlde-bore circular tubes (CT). This method was fully investigated in theory. A flat tube with a 2a×ka-mm (2a<ka) channel develops the maximum radial temperature gradient (π/k)-1 times less than an a -mm i. d. circular one. Compared with a 2a-ram i. d. circular tube, the flat one has at least a ((2k/π)-1)-fold increase in absorption response or decrease in detection limits, and the same fold increase in allowable sample throughput. The highest efficiency with a flat tube is thus expected. These were all tested in electrophoresis with 0.2×0.6-mm, 0.2-ram i. d. and 0.4-mm i. d. plastic tubes. Besides, the 0.2×0.6-mm flat tube required a less recovery time than the 0.2-mm i. d. tube and allowed a higher working voltage than the 0.4-mm i. d. tube, which implied that the flat tube offered the highest speed. The optimum k was observed at the values of 6—10 in the experiment and the recovery time was affected by the size of the tube and the viscosity of the solution.A preparation process of flat fluorocarbon polymer tubes is described in the paper, with a discussion on heat-deformatlon of the flattened tube.展开更多
基金supported by the Natural Science Foundations of Hebei(NoB2010000657)
文摘A novel micelle to solvent stacking on-line sample preconcentration technique in capillary zone electrophoresis（MSS-CZE） has been developed to determine the strychnine and brucine in traditional Chinese medicine preparations.The optimal running buffer was 30 mmol/L H_3PO_4 containing 20%acetonitrile at pH 4.0.The sample matrix was 8 mmol/L H_3PO_4 containing 5 mmol/L sodium dodecyl sulfate（SDS） at pH 3.0.The established MSS-CZE method afforded more than 50-fold improvements in concentration sensitivity compared with typical CZE-UV analysis.The calibration curve was linear in the range from 0.2 to 15.0μg/ mL for both strychnine and brucine,with correlation coefficients of 0.9984 and 0.9976,respectively.The limits of detection（5/ N = 3：1） for strychnine and brucine were 0.02 and 0.05μg/mL,respectively.The MSS-CZE method has been successfully applied to the analysis of strychnine and brucine in Chinese medicinal preparations.
基金supported by the National Science and Technology Major Project for Major Drug Development(No.2013ZX09508104)the Traditional Chinese Medicine Industry Research Special Project(No.201307002)the National Science&Technology Major Project Key New Drug Creation and Manufacturing program(No.2011ZX09307002-03)of the People's Republic of China
文摘A sample enrichment method focusing on the minor targeted components was established to help them to be successfully separated by pH-zone refining CCC.Seven minor indole alkaloids in Uncaria rhynchophylla(Miq.)Miq.ex Havil(UR)were chosen to show the advantage of this method.The sample enrichment and separation were
文摘Zone electrophoresis is suggested with flat capillary instead of circular ones to get over the disadvantages of both the narrow-bore and wlde-bore circular tubes (CT). This method was fully investigated in theory. A flat tube with a 2a×ka-mm (2a<ka) channel develops the maximum radial temperature gradient (π/k)-1 times less than an a -mm i. d. circular one. Compared with a 2a-ram i. d. circular tube, the flat one has at least a ((2k/π)-1)-fold increase in absorption response or decrease in detection limits, and the same fold increase in allowable sample throughput. The highest efficiency with a flat tube is thus expected. These were all tested in electrophoresis with 0.2×0.6-mm, 0.2-ram i. d. and 0.4-mm i. d. plastic tubes. Besides, the 0.2×0.6-mm flat tube required a less recovery time than the 0.2-mm i. d. tube and allowed a higher working voltage than the 0.4-mm i. d. tube, which implied that the flat tube offered the highest speed. The optimum k was observed at the values of 6—10 in the experiment and the recovery time was affected by the size of the tube and the viscosity of the solution.A preparation process of flat fluorocarbon polymer tubes is described in the paper, with a discussion on heat-deformatlon of the flattened tube.
