分散固相萃取-高效液相色谱-串联质谱法测定水稻和土壤中的福美双与甲霜灵残留

建立了一种同步分析水稻和土壤中福美双和甲霜灵残留的分散固相萃取-高效液相色谱-串联质谱(HPLC-MS/MS)检测方法。样品经乙腈提取,PSA、C18吸附剂净化,C18色谱柱分离,0.2%甲酸水-乙腈等度洗脱,质谱采用电喷雾正离子(ESI+)模式电离,多反应离子监测模式定性分析,基质匹配标准曲线外标法定量。结果表明:在1~500μg/L浓度范围内,不同基质中的福美双和甲霜灵的线性相关系数均大于0.991。在0.01~1.5 mg/kg添加水平范围内,土壤、水稻植株、稻壳和糙米样品中福美双和甲霜灵的日内平均回收率为76%~104%,日内相对标准偏差(RSD)为1.2%~13.2%(n=5);日间平均回收率为74%~102%,日间RSD为2.8%~10.4%(n=5)。该方法简单、快速、灵敏度及准确度高,能够满足水稻及土壤中福美双和甲霜灵残留量的检测要求。

Simultaneous determination of thiram and metalaxyl residues in rice and soil by dispersive solid phase extraction and high performance liquid chromatography-tandem mass spectrometry

A rapid analytical method for the simultaneous determination of thiram and metalaxyl in paddy soil, rice plant, rice husk and brown rice was developed using dispersive solid phase extraction and high performance liquid chromatography-tandem mass spectrometry(HPLC-MS/MS). The analytes was extracted by acetonitrile and cleaned up by PSA and C18, and then separated on a reversed phase C18 column using an isocratic elution program of 0.2% aqueous formic acid and acetonitrile. Qualitative analysis was performed with electrospray ionization in positive mode(ESI+) under multiple reaction monitoring(MRM) mode. Matrix-matched calibrations were respectively used to quantify the residue concentrations. In the concentration range of 1-500 μg/L, the matrix-matched calibration curves showed good linearity with correlation coefficients >0.991. Intra-day mean recoveries of thiram and metalaxyl in different matrices were found between 76% and 104% at 0.01-1.5 mg/kg, with relative standard deviations(RSD) of 1.2%-13.2%(n=5). Inter-day mean recoveries of thiram and metalaxyl were found between 74% and 102% with RSD of 2.8%-10.4% at 0.01-1.5 mg/kg(n=5). The method is simple, rapid, sensitive and accurate, which can meet the detection requirements of thiram and metalaxyl residues in rice samples and soil.