基质固相分散-高效液相色谱法测定玉米中 7种苯氧羧酸类除草剂的残留

采用基质固相分散-高效液相色谱法(MSPD-HPLC)测定了7种苯氧羧酸类除草剂在玉米中的残留。玉米样品与基质固相分散介质C18化学键合硅胶(ODS)一起研匀得到基质固相分散体系,将其填入事前装有弗罗里硅土的净化柱中,以环己烷洗去油脂等杂质,再用乙酸乙酯洗脱得到分析液;在反相高效液相色谱(RP-HPLC)柱上,分析液经ODS柱以甲醇-水(体积比65∶ 35)为流动相洗脱,用紫外检测器检测,以外标法定量。在0.1和1.0 mg/kg添加水平下,7种苯氧羧酸类除草剂在玉米中的添加回收率为80% ~110%,相对标准偏差RSD为3.6% ~10.3%,检出限在7.9 ~12.6 μ g/kg之间。

Residual analysis of 7 phenoxyacid herbicides in corn by MSPD-HPLC

A rapid method based on matrix solid phase dispertion(MSPD) extraction with octadecyl silane (ODS) and co-column purification with florisil was developed for the determination of 7 phenoxyacid herbicides in corn using reversed-phase high performance liquid chromatography (RP-HPLC) with UV detector,quantified with external standard calibration method.The column was eluted with cyclohexane to remove the impurities,and then eluted with ethyl acetate to get the analytes which were analyzed by HPLC.The chromatographic separation was performed on an ODS column using mobile phases based on mixtures of methanol:water (35∶ 65,V/V).At the fortified levels of 0.1 and 1.0 mg/kg,the average recoveries ranged from 80% to 110%,with relative standard deviations between 3.6% and 10.3%.Limits of detection for corn ranged form 7.9 to 12.6 μ g/kg.