离子对液相色谱法测定稻米中苯并咪唑类农药残留

Determination of Benzimidazoles Residues in Rice by Ion Pair High Performance Liquid Chromatography

建立了以分散固相萃取技术净化，高效液相色谱分离和检测稻米中苯并咪唑类农药及其代谢物残留的方法。样品中多茵灵、甲基托布津、噻菌灵等3种苯并咪唑农药及其代谢物2-氨基苯并咪唑经乙腈提取，乙二胺-N-丙基硅烷（PSA）和无水硫酸镁净化，以癸烷磺酸钠离子对试剂与甲醇混合液为流动相，经反相C18柱分离二极管阵列检测器（DAD）波长切换测定，外标法定量；检出限在0．02～0．06mg／kg之间，样品回收率76．0％-114．3％，相对标准偏差为1．9％-13．4％。本方法操作快速简便，灵敏度高，能满足农药残留分析的要求。

A high performance liquid chromatographic （HPLC） method for multi - residue analysis of benzimid- azoles and the derivative residues in rice had been established. Three kinds of benzimidazoles carbendazim, thio- phanate -methyl, thiabendazole and their derivative 2 -aminobenzimidazole were extracted with acetonitrile from rice samples, being cleaned up by PSA dispersive solid - phase extraction, and then being separated on a 250 mm × 4.6 mm i. d. ,C18 column of 5 μm particle size by pre -mixed mobile phase of decanesulfonate sodium ion pair reagent and methanol;finally detected by photodiode array detector （DAD） with wavelength switch. Measured in fortified rice at 3 spiked levels, the average recoveries of 3 repeats were in the range of 76.0%- 114.3% with relative standard de- viations 1. 9%- 13.4% and the limit of detection （LOD） was 0.02 - 0.06 mg/kg. The method is simple, quick, sen- sitive and is qualified for multi -residue analysis.