Department of Chemistry, Lanzhou University, Lanzhou 730000, China.
J Chromatogr A. 2009 Dec 4;1216(49):8665-70. doi: 10.1016/j.chroma.2009.10.027. Epub 2009 Oct 14.
Transient isotachophoresis (tITP) can improve the sensitivity of capillary electrophoresis (CE). In general, it was carried out under the condition of suppressed electroosmotic flow (EOF). However, some special conditions, such as extreme low pH background electrolyte and coating were needed to achieve the requirements of suppressed EOF. In this work, an approach of tITP under the strong counter-EOF in open system (counter-EOF-tITP) is presented for the rapid and sensitive preconcentrating the reduced glutathione (GSH) and the oxidized glutathione (GSSG) without modifying the capillary and the commercial CE instrument. The parameters of the experimental system, such as the concentration of leading electrolyte, the injected amount of terminating electrolyte and the injected pressure of sample were investigated in detail to understand the mechanism of counter-EOF-tITP. The sensitivity enhancement factors were of 320 for GSH and 280 for GSSG. In addition, the detection limit of 23.4 and 18.0 microg L(-1) for GSH and GSSG was achieved, respectively. The method's applicability was demonstrated by determining GSH and GSSG in tomato and human serum.
瞬时等速电泳（tITP）可以提高毛细管电泳（CE）的灵敏度。通常，它是在抑制电渗流（EOF）的条件下进行的。然而，一些特殊条件，如极端低 pH 的背景电解质和涂层，需要达到抑制 EOF 的要求。在这项工作中，提出了一种在开放系统中强反电渗流下进行 tITP 的方法（反电渗流-tITP），用于快速灵敏地预浓缩还原型谷胱甘肽（GSH）和氧化型谷胱甘肽（GSSG），而无需修饰毛细管和商业 CE 仪器。详细研究了实验系统的参数，如先导电解质的浓度、终止电解质的注入量和样品的注入压力，以了解反电渗流-tITP 的机制。GSH 的灵敏度增强因子为 320，GSSG 的灵敏度增强因子为 280。此外，GSH 和 GSSG 的检测限分别达到 23.4 和 18.0μg/L。该方法通过测定番茄和人血清中的 GSH 和 GSSG 验证了其适用性。
