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.