QuEChERS-超高效液相色谱-四极杆-飞行时间质谱法同时测定土壤中23种农药

Simultaneous Determination of 23 Pesticides in Soil by QuEChERS-UPLC-Quadrupole-Time of Flight MS

[目的]利用QuEChERS前处理法-超高效液相色谱(UHPLC)-四极杆-飞行时间质谱(Q-TOF/MS)法建立了23种农药的快速筛查和定量检测方法。[方法]建立了23种农药的一级精确质量数和二级图谱库数据库。通过谱库信息比对,该方法可实现无标准品情况下23种农药的定性鉴定。土壤样品经过QuEChERS前处理法进行提取,采用C18色谱柱分离,0.1%甲酸10 mmol/L乙酸铵甲醇溶液和0.1%甲酸10 mmol/L乙酸铵水进行梯度洗脱,外标法定量。[结果]在线性范围内,23种农药的线性关系良好,线性相关系数≥0.991。方法的定量限为5μg/kg。23种农药的平均回收率为65.91%~108.6%,相对标准偏差(RSD)为0.07%~16.00%。[结论]该方法操作简单、稳定性好,可满足土壤中23种农药残留的检测要求。

[Aims]A rapid screening and detection method for 23 pesticides in soil was established by combining QuEChERS with ultra high performance liquid chromatography(UPLC)-quadrupole-time of flight mass spectrometry(Q-TOF/MS).[Methods]A database including accurate mass and fragment ions information of 23 pesticides was established.Based on the above database,the qualitative identifications of the 23 pesticides were accomplished without comparison to the standard substances.Soil samples were pretreated by QuEChERS and separated by C18 column.Gradient elution of methanol solution which contained 0.1%formic acid 10 mmol/L ammonium acetate and water solution containing 0.1%formic acid 10 mmol/L ammonium acetate was carried out.External standard method was set for quantitative.[Results]The linear correlation coefficients of 23 pesticides were more than 0.991.The limits of quantitation(LOQs)of the method were 5μg/kg.The average recoveries at three spiked levels of 23 pesticides were65.91-108.6%with the relative standard deviation(RSD)0.07-16.00%.[Conclusions]With the advantages of simplicity and good stability,this method is available for the determination of 23 pesticide residues in soil.