QuEChERS法萃取-气相色谱-三重四级杆串联质谱法检测大葱等鳞茎类蔬菜中6种杀菌剂的分析方法

QuEChERS-GC-MS/MS method for determination of 6 pesticide residues in onion and other bulb vegetables

目的:建立QUECHERS法提取大葱等鳞茎类蔬菜中百菌清、菌核净、粉锈宁、甲霜灵、异菌脲和溴氰菊酯农药气相色谱-三重四级杆串联质谱法检测的分析方法。方法:取鳞茎类蔬菜,置粉碎机中粉碎,准确称取样品12.0g,置塑料离心管中,加丙酮-环己烷(V∶V=1∶1)溶液20mL,再加入QuEChERS萃取包进行萃取;萃取液转移至QuEChERS净化管中净化。取上清液10mL氮吹至近干,残渣加丙酮溶液1.0mL,0.45μm滤膜滤过,上GC-MS/MS仪,内标法定量检测。结果:在0.04~10.0μg/mL范围内,6种杀菌剂质量浓度同响应值具有良好的线性关系,相关系数均大于0.995;检出限均0.0020~0.0062 mg/kg范围内;平均加标回收率在84.2~104.2%之间;6次进样重复性相对标准偏差(RSD)均在5.0%以内(n=6)。结论:该方法提取周期短,使用溶剂少,准确性好,适用于批量样品大葱等鳞茎类蔬菜中农药残留的监测。

Bulb vegetable samples were crushed in a grinder.12 g sample was taken and placed in a plastic centrifugal tube,20 mL acetone-cyclehexane(V∶V=1∶1)solution and QuEChERS extraction package were added into the tube.The extract was purified in QuEChERS purification tube.10 mL supernatant was taken and flowed to near dry by nitrogen.The residue was volumned to 1 mL with acetone solution,filtered with 0.45μm filter membrane,and quantified by internal standard method on GC-MS/MS instrument.There was a good linear relationships between the mass concentration of the 6 fungicides(chlorothalonil,dimetachlone,triadimefon,metalaxyl,iprodione and deltamethrin)and the response value,in the concentration range of 0.04-10.0μg/mL,the correlation coefficients were all greater than 0.995.The detection limits were in the range of 0.0020-0.0062 mg/kg.The average recoveries of samples were ranged from 84.2%to 104.2%.The relative standard deviations(RSD)of repeatability were all less than 5%(n=6).This method has the advantages of short extraction period,less solvent and good accuracy,and is suitable for monitoring of pesticide residues in bulb vegetables such as scallion.