QuEChERS方法联合HPLC-MS/MS和GC-MS测定土壤中110种农药残留

采用Qu ECh ERS前处理方法联合高效液相色谱串联二级质谱(HPLC-MS/MS)和气相色谱串联质谱(GC-MS),建立了测定土壤中110种农药残留的方法。通过调整加入水中的乙酸含量对Qu ECh ERS方法进行优化,结果表明加入1%的乙酸提高了农药的回收率。基于农药的极性、热稳定性、挥发性等特性差异,分别采用HPLC-MS/MS测定其中的43种农药和GC-MS测定另外的67种农药。采用内标法测定回收率,内标为阿特拉津-d5、磺酰磺隆、1,3-二甲基-2-硝基苯、磷酸三苯酯、苝-d12。在3个添加水平(10、20、50μg·kg~(-1))下,由HPLC-MS/MS测定的43种农药的平均回收率范围为59.1%~129.4%,相对标准偏差(RSD)在0.3%~15%之间;由GC-MS测定的67种农药的平均回收率范围为44.9%~168.1%,RSD在0.5%~20%之间。方法的检出限范围为0.01~5.00μg·kg~(-1)。采用该方法检测某土壤样品,共检出农药68种,其中主要包括烟嘧磺隆、炔苯酰草胺、乙氧氟草醚、灭菌丹、烯酰吗啉、高效氯氟氰菊酯和部分有机磷、有机氯农药等,结果表明该方法简单有效、检测灵敏度高,可用于土壤中农药多残留的检测。

Development of a multiresidue method for determination of 110 pesticide residues in soil using QuEChERS-HPLC-MS/MS and QuEChERS-GC-MS

A method was established for the determination of 110 pesticides in soil using high performance liquid chromatography tandem mass spectrometry(HPLC-MS/MS)and gas chromatography tandem mass spectrometry(GC-MS)with modified QuEChERS(Quick, Easy, Cheap, Effective, Rugged, and Safe). Levels of acetic acid used in the QuEChERS procedure were optimized, and results indicated that higher recoveries were obtained when 1%acetic acid was added. Based on differences in polarity, thermostability, volatility, and other char-acteristics of pesticides, analysis of 43 pesticides was conducted via HPLC-MS/MS and the other 67 pesticides were analyzed using GC-MS. Five internal standards(atrazine-d5, sulfosulfuron, 1,3-dimethyl-2-nitrobenzene, triphenyl phosphate, and perylene-d12)were used for the method validation. The average recoveries of the 43 pesticides analyzed via HPLC-MS/MS at three spike levels(10, 20, and 50μg·kg-1) ranged from 59.1%to 129.4%with relative standard deviations(RSDs)between 0.3%and 15%;whereas the average recoveries of the 67 compounds analyzed using GC-MS ranged from 44.9%to 168.1%with RSDs of 0.5%~20%. The detection limits of the method ranged from 0.01 to 5.00μg·kg-1. The established method was used to determine pesticide resides in a soil sample, in which 68 pesticides were found, including nicosulfuron, propyzamide, oxyfluorfen, folpet, dimethomorph, lambda-cyhalothrin, some organophosphorus pesticides, and some organochlorine pesticides. Overall, the method is simple, efficient, and sensitive, and thus can be used for the simultaneous determination of pesticide residues in soil.