毛细管电泳安培检测扑热息痛及其水解物

研究了各种电化学预处理条件下碳纤维电极对扑热息痛及水解物的电化学行为。确定该体系最佳预处理条件为０．２Ｖ电位下阳极化１ｍｉｎ，再于－２．０Ｖ下阴极化１０ｓ。预处理后的碳纤维伏安响应得到明显提高。运用最佳条件并在支持电解中加入添加剂后，扑热息痛及其水解物在毛细管电泳上获得很好的分离和检测。其中扑热息痛的检测下限为２．７８ｐｇ；对氨基酚为１．８４ｐｇ。

Determination of Acetaminophen and Its Hydrolysate by Capillary Electrophoresis-Electrochemical Detection

An electrochemical pretreatment for carbon fiber in diameter of 30 um microelec-trode was optimized for the determination of acetaminophen and its hydrolysatc (p-aminophenol) by capillary electrophoresis-electrochenistry (CEEC). Pretreatment is characterized with respect to potential range, duration of applied potential and solution conditions. Carbon fiber microclectrode exhibits substantial enhancement of the voltammetric response of acetaminophen and p-aminophenol after the optimal pretreatment selected as an anodiza tion at + 2. 0 V(vs. Ag/AgCl) for 1 min followed by a cathodisation at - 2. 0 V for 10 s in phosphate buffer (pH = 7. 0). Under the optimized condition and with the addition of 1.2 propanediol into the phosphate supporting electrolyte, acetaminophen and p-aminophenol were separated satisfactorily and eluted by CEEC within 10 min. The detection limits of acetaminophen and p-aminophenol were 2. 78 and 1. 84 pg, respectively.