QuEChERS-超高效液相色谱-串联质谱测定青贮牧草中23种农药残留

Simultaneous determination of 23 pesticides residues in silage forage grass by QuEChERS-based ultra-high performance liquid chromatography-tandem mass spectrometry

采用改进的QuEchERS前处理方法结合超高效液相色谱串联质谱(UPLC-MS/MS),建立了青贮皇竹草中23种农药残留的检测方法。样品经超纯水浸泡,1%甲酸乙腈提取,无水MgSO_(4)、乙二胺-N-丙基硅烷(PSA)、十八烷基硅烷(C_(18))和石墨化炭黑(GCB)基质分散净化,Agilent ZORBAX Eclipse Plus C_(18)色谱柱分离,电喷雾串联质谱多反应监测(MRM)模式测定。23种农药在0.5~20μg/L范围内线性关系良好(R^(2)>0.9986),检出限为0.002~0.1μg/kg,定量限为0.005~0.2μg/kg。在0.5,1,5μg/kg 3个添加浓度水平下,回收率在76.2%~105.9%,相对标准偏差(RSD)在2.3%~11%。该方法适用于青贮皇竹草中23种农药的定性定量分析。

A method was developed for the simultaneous determination of 23 kinds of pesticides in silage Pennisetumsinese Roxb using QuEChERS-based extraction and ultra-high performance liquid chromatography tandem mass spectrometry(UPLC-MS/MS).Silage Pennisetumsinese Roxb sample was immersed in ultrapure water,extracted with 1%formic acid acetonitrile solution,purified with a matrix dispersion of anhydrous magnesium sulfate(MgSO_(4)),primary secondary amine(PSA),octadecylsilane(C_(18))and graphitized carbon black(GCB),separated by Agilent ZORBAX Eclipse Plus C_(18)column,and analyzed by multiple reaction monitoring(MRM)mode.The 23 kinds of pesticides display good linearities in the range of 0.5-20μg/L(R^(2)>0.9986),with the limits of detection of 0.002-0.1μg/kg,and the limits of quantification of 0.005-0.2μg/kg.At the spiked amounts of 0.5,1 and 5μg/kg,the recoveries were in the range of 76.2%-105.9%,with the relative standard deviations between 2.3%and 11%.The method is suitable for the qualitative and quantitative analyses of 23 kinds of pesticides in silage Pennisetumsinese Roxb.