QuEChERS-HPLC-Q-TOF/MS快速筛查蔬菜中32种农药残留

建立了QuEChERS-高效液相色谱-四极杆-飞行时间质谱法用于蔬菜中32种农药残留的快速筛查与确证分析方法。乙睛为提取剂,氯化钠盐析,C18和PSA为净化剂,电喷雾正离子扫描。通过TOF MS-IDA-MS/MS扫描模式,一次采集即可同时获得农药分子的一级精确质量数和二级质谱图信息。在线性范围内32种化合物线性关系良好,相关系数均大于0.9990,在三个加标水平(1,4和20 LOQ)下的平均回收率为70.41%~103.1%,相对标准偏差为1.2%~11.2%,方法检出限LOD为0.3~1.3μg/kg,定量限LOQ为1.0~4.0μg/kg。与国标相比,大大缩短前处理时间;此外,该方法中吡虫啉、虫酰肼等9种农药的方法检出限得到了有效降低;除乙霉威和嘧菌酯回收率略低,其它30种农药回收率均无明显差别。该方法简单快速、高效准确、灵敏度高,能够快速筛查和分析蔬菜中残留农药。

Rapid Screening of 32 Pesiticides Residues in Vegetables by QuEChERS-HPLC-Q-TOF/MS

An analytical method for rapid screening and accurate quantification of 32 pesticides in vegetables was developed using QuEChERS cleanup with high-performance liquid chromatography coupled with quadrupole-time of flight mass spectrometry(HPLC-Q-TOF/MS).The samples were extracted with acetonitrile,salted out with sodium chloride,and then cleaned up with C18 and PSA.The accurate mass and fragment ions of 32 pesticides were simultaneously created using TOF MS-IDA-MS/MS acquisition in a single run.The correlation coefficients(r)were more than 0.9990 in the linear range of 32 pesticides.The average recoveries of the 32 pesticides at three spiked levels(1,4 and 20 LOQ)varied from 70.41%-103.1%with the relative standard deviations ranging from 1.2%to 11.2%.The limits of detection(LOD,S/N≥3)were 0.3-1.3μg/kg,and the limits of quantitation(LOQ,S/N≥10)were 1.0-4.0μg/kg.Compared with the national standard,the pretreatment time was greatly shortened.In addition,the detection limits of nine pesticides such as imidacloprid and tebufenozide in this method were effectively reduced.The recovery rates of the other 30 pesticides were not significantly different except for diethofencarb and azoxystrobin.The method was simple,fast,accurate and sensitive,and it could quickly screen and analyze pesticide residues in vegetables.