胶束电动毛细管电泳法分离检测5种β-内酰胺类抗生素

Separation and Determination of Five β-Lactam Antibiotics by Micellar Electrokinetic Capillary Chromatography

采用毛细管电泳法,基于胶束电动模式与有机添加剂协同作用,分离检测5种β-内酰胺类抗生素。考察运行缓冲液的构成及各组分浓度、pH值、分离电压等因素对电泳分离的影响。优化后的电泳运行缓冲液包含20mmol/L Na2HPO4-20mmol/L NaH2PO4(pH8.5),20mmol/L十二烷基硫酸钠和体积分数25%甲醇。在18kV电压下5种抗生素在15min内达到基线分离。各组分线性关系良好,检出限5.3～8.1mg/L,进样精密度RSD 3.8%～5.5%。研究表明,对分子结构特别相近的抗生素,通过表面活性剂胶束准固定相与有机添加剂协同作用来改善分离效果是可行的。

Micellar electrokinetic capillary chromatography（MECC） coupled with the addition of methanol to the running buffer was used for the separation and determination of five β-lactam antibiotics,ceftiofur,cephazoline,cephalexin,ampicillin and penicillin G.The running buffer was optimized to consist of 20 mmol/L Na2HPO4,20 mmol/L NaH2PO4（pH 8.5）,20 mmol/L SDS and 0.25（V/V） methanol.Under the voltage of 18 kV,baseline separation was achieved for the five antibiotics within 15 min,and their concentrations and peak areas exhibited a good linear relationship.The detection limits for these antibiotics were between 5.3 and 8.1 mg/L.The precision of the method was found to be 3.8%-5.5%.The results indicate that the combination of micellar pseudostationary phase and organic additives enables highly efficient chromatographic separation of antibiotics of very similar structures.