Determination Methods of Multi-class Herbicide Residues in Corn Using UPLC Method

[Objective] To detect the residues of nine types of herbicide belonging to four categories in maize using UPLC method.[Method] The QuEChERS method was used for sample pretreatment.ACQUITY UPLC BHE C18(2.1 mm×50.0 mm,1.7 μm) was selected as chromatographic column with 0.05% H3PO4 in water as mobile phase A and 0.05% H3PO4 in methyl cyanide as mobile phase B.[Result] A good baseline separation of target compounds was obtained in 4.5 minutes.The limit of detection was 15-30 μg/kg and the limit quantification was 30-60 μg/kg.The calibration of nine herbicides all showed high correlation coefficients over their respective ranges,with correlation coefficients above 0.999.Recoveries of herbicides at three spiked concentration levels ranged from 79.5% to 98.8%,with relative standard deviations(RSD,n=5) between 2.0% and 9.6%.[Conclusion] This method is simple,efficient and accurate.Therefore,it is practicable in the trace determination of herbicide.