UPLC法同时测定玉米中不同类型除草剂残留的方法

[目的]建立玉米中4种不同类型的9种除草剂残留量的超高效液相色谱(UPLC)检测方法。[方法]样品前处理采用QuEChERS方法,以ACQUITY UPLC BHE C18(2.1 mm×50.0 mm,1.7μm)为色谱柱,以水(含0.05%H3PO4)、乙腈(含0.05%H3PO4)为流动相。[结果]在优化的条件下,9种除草剂在4.5 min内实现基线分离;检测限和定量限分别为15～30和30～60μg/kg;在各自的浓度范围内,线性关系良好,相关系数(r)均大于0.999;在高、中、低3个水平的加标回收率为79.5%～98.8%,方法的标准偏差(RSD,n=5)为2.0%～9.6%。[结论]该方法简便、高效、准确,为除草剂残留的常规检测提供了一种省时、可行的新方法。

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.