柱前衍生化后用离子对高效液相色谱法测定牛奶中的苄青霉素、苯唑西林、氯唑西林和双氯西林。

Determination of benzylpenicillin, oxacillin, cloxacillin, and dicloxacillin in cows' milk by ion-pair high-performance liquid chromatography after precolumn derivatization.

作者信息

Marchetti M, Schwaiger I, Schmid E R

机构信息

Institute of Analytical Chemistry, University of Vienna, Austria.

出版信息

Fresenius J Anal Chem. 2001 Sep;371(1):64-7. doi: 10.1007/s002160100858.

DOI:10.1007/s002160100858

PMID:11605761

Abstract

A high-performance liquid-chromatographic method has been developed for the determination of five penicillin compounds (benzylpenicillin, phenoxymethylpenicillin, oxacillin, cloxacillin, and dicloxacillin) at trace levels in commercially available milk samples. This method comprises extraction of the lipids with ethyl acetate, clean-up and concentration on a C-18 solid-phase extraction column, and derivatization with 1,2,4-triazole and mercury(II) chloride solution, pH 8, at 65 degrees C for 10 min. The derivatized compounds are eluted from a C-2 column with a mobile phase containing acetonitrile and phosphate buffer loaded with sodium thiosulfate and tetrabutylammonium hydrogen sulfate as ion-pairing reagent. The limit of determination was found to be 4 microg L(-1) milk for benzylpenicillin and 10 microg L(-1) for the others. This meets EU criteria according to decision No. 93/256/EEC.

摘要

已开发出一种高效液相色谱法，用于测定市售牛奶样品中痕量水平的五种青霉素化合物（苄青霉素、苯氧甲基青霉素、苯唑西林、氯唑西林和双氯西林）。该方法包括用乙酸乙酯萃取脂质，在C-18固相萃取柱上进行净化和浓缩，以及在65℃下用1,2,4-三唑和pH为8的氯化汞（II）溶液衍生化10分钟。衍生化后的化合物用含有乙腈和磷酸盐缓冲液的流动相从C-2柱上洗脱，该磷酸盐缓冲液中加入硫代硫酸钠和硫酸氢四丁铵作为离子对试剂。苄青霉素的测定限为4 μg L⁻¹牛奶，其他化合物为10 μg L⁻¹。根据第93/256/EEC号决定，这符合欧盟标准。