QuEChERS–超高效液相色谱–串联质谱法测定果蔬中57种农药残留量

Determination of 57 pestcide residues in fruits and vegetables by QuEChERS–ultra performance liquid chromatography–tandem mass spectrometry

建立同时测定果蔬中57种农药的QuEChERS–超高效液相色谱–串联质谱的分析方法。样品以乙腈提取,经氯化钠盐析分层,上清液经PSA、石墨炭黑(GCB)、C_(18)混合净化剂净化,经C_(18)色谱柱分离,用含0.1%甲酸的5 mmol/L乙酸铵水溶液和乙腈梯度洗脱,多反应监测(MRM)正离子模式扫描,外标法定量。57种农药的质量浓度在2～50μg/L范围内与色谱峰面积呈良好的线性关系,线性相关系数(r)大于0.99,方法的定量下限为0.010mg/kg,在0.020,0.050,0.10 mg/kg的加标水平下,平均回收率在74%～104%之间,测定结果的相对标准偏差小于11%(n=6)。该方法操作简单、快速、灵敏度高,适用于大批量果蔬样品中农药多残留的快速分析。

A multiresidue analytical method for the determination of 57 pesticide residues in fruits and vegetables by QuEChERS–ultra performance liquid chromatography–tandem mass spectrometry was developed. The target compounds were extracted with acetonitrile, and salted out with sodium chloride, purified by mixed purifier, primary secondary amine（PSA）,graphitized carbonblack （GCB） and C18, then separated on C18 column with 0.1% formic acid aqueous solution containing 5 mmol/L ammonium acetate-acetonitrile as mobile phases under gradient elution. The positive ion mode and multiple reaction monitoring （MRM） mode were used in the analysis,and the analytes were quantified by external standard method. The concentration of 57 pesticide residues was linear with its chromatographic peak area in the range of 2–50 μg/L with correlation coefficients （r） more than 0.99. The quantification limits of 57 pesticides were 0.010 mg/kg. In 0.020, 0.050, 0.10 mg/kg adition level, the recoveries were in the range of 74%–104%, and the relative standard deviations of detection results were less than 11%（n=6）. The developed method is simple, rapid, and sensitive, it is suitable for the rapid determination of pesticide residues in fruits and vetetables.