药物头孢Ⅳ号和氨苄青霉素及其生物合成前体的毛细管区带电泳分离

研究了同分异构体药物头孢Ⅳ号和氨苄青霉素及其目标生物合成前体三肽Ｄ－苯丙氨酸－Ｌ－半胱氨酸－Ｄ－缬氨酸、Ｌ－苯丙氨酸－Ｌ－半胱氨酸－Ｄ－缬氨酸的毛细管区带电泳分离。结果表明，采用含１２ｍｍｏｌ／Ｌ二甲基β－环糊精（ＤＭ－β－ＣＤ）的５０ｍｍｏｌ／ＬＴｒｉｓ－Ｈ３ＰＯ４缓冲溶液（ｐＨ２．３）既可将头孢Ⅳ号和氨苄青霉素分离，又可将Ｄ－苯丙氨酸－Ｌ－半胱氨酸－Ｄ－缬氨酸、Ｌ－苯丙氨酸－Ｌ－半胱氨酸－Ｄ－缬氨酸分离。     

毛细管电泳的原理和应用(第六讲)CE在DNA、糖和离子分析中的应用

简要介绍了ＣＥ在ＤＮＡ、糖和离子分析中的应用。ＤＮＡ分析包括分离原理、方法及检测手段，碱基、核苷和核苷酸分析，纯度检测和微量制备，ｓｓＤＮＡ和ｄｓＤＮＡ分析，基因突变检测及ＤＮＡ序列分析等。糖分析包括衍生化技术、检测方法、所用模式及糖复合物的分析等。离子分析包括阴离子分析原理、检测方法、影响因素、应用及阳离子分析等。     

Deductive prediction of measurement precision and optimization of integration time and wavelength in capillary electrophoreses

Summary This paper demonstrates that the relative standard deviation (RSD) of measurements in a capillary electrophoresis system can be predicted theoretically from the baseline and the signal shape at low sample concentration. The only requirements for prediction of the uncertainty are the Fourier transform of the baseline (here 2048 data points) and the observation of signal shape. The micellar electrokinetic chromatography (MEKC) of acetaminophen and caffeine is taken as an example. The optimum is defined here as the condition of the lowest RSD or highest precision. The optimum single wavelength is selected from between 220 and 350 nm for the MEKC system equipped with a photodiode array detector. The optimum time domain of signal integration is shown to be even narrower than the entire signal region, providing an RSD value about half that for integration of the entire region. The theory is in good agreement with observed RSD values.     

电泳力学迁移模型（Ⅱ）──SDS－蛋白质在无胶筛分电泳中的迁移规律

在不同操作电压和温度下，ＳＤＳ－蛋白质在无胶筛分电泳的实验结果表明，电泳力学迁移模型（ＥＭＭＭ）比传统经验式更能准确地反映实验事实．ＳＤＳ－蛋白质对构象参数（Ｒｃ）随热力学温度增加而变化，在２８８—２９８Ｋ范围内Ｒｃ迅速变小，而在２９８～３１３Ｋ范围内，温度变化对其影响不大．不同的ＳＤＳ－蛋白质在一定条件下具有相近的活化能，该结论进一步从热力学方面支持了ＥＭＭＭ的一个基本结论，即不同相对分子质量Ｍｒ的ＳＤＳ－蛋白质在同一ＮＧＳ实验条件下具有相似的形状或构象，并与ＳＤＳ－蛋白质分子为长棒状这一客观事实相符合．     

A new approach to the studies of submicron particle suspensions based on the effect of pressure in capillary zone electrophoresis

A new approach based on the effect of pressure in CZE is suggested for acceleration of particle migration in electrophoretic runs resulting in reduction of the analysis time. It provides conditions for studying fast processes in suspensions. The effect of pressure on the migration of silica spheres with average diameters of 100, 150, and 390 nm was studied by CZE at an applied voltage of 25 kV. The particle hydrodynamic behavior was also investigated under the same capillary dimensions and BGE composition. The total particle mobility (excluding the average flow rate) was found to increase with increasing the pressure applied and particle size. The particle migration mechanism explaining the effect of pressure on particle velocity was shown to be almost the same as in wide‐bore hydrodynamic chromatography. It is based on changing radial distribution of particle concentration along the capillary cross section depending on particle diffusivity. On the basis of this mechanism appearance of a zone of negatively charged particles in electropherograms ahead of the marker peak can be explained.