液相色谱-串联质谱法测定苹果中水胺硫磷

建立苹果中水胺硫磷残留的液相色谱-串联质谱检测方法。样品以乙腈提取,采用电喷雾正离子源(ESI~+)和多重反应监测(MRM)模式测定,基质匹配标准曲线定量。结果表明:苹果基质中,水胺硫磷色谱峰面积响应值与其质量浓度呈良好线性关系(r~2=0.999),方法的线性范围为0.3~100μg/L,检出限为0.15μg/L,定量限为0.5μg/L。在5,50,100μg/kg添加水平下,水胺硫磷回收率为77.3%~95.2%,测定结果的相对标准偏差为5.7%~8.9%(n=6)。方法精密度和准确度满足残留限量监测要求。

Determination of the Isocarbophos Residues in Apple by Liquid Chromatography-Tandem Mass Spectrometry

A new method was established for the determination of isocarbophos residues in apple by liquid chroma-tography–tandem mass spectrometry. The test sample was extracted with acetonitrile, electrospray positive ion source(ESI+) and multiple reaction monitoring mode (MRM) and matrix-matched external standard method were applied. The calibration curve showed good linearity with the correlation coefficient of 0.999, the linear range was 0.3–100 μg/L, the detection limit was 0.15μg/L, and the quantification limit was 0.5μg/L. With addition of 5, 50, 100μg/kg, the recoveries were 77.3%–95.2%, and the relative standard deviation was 5.7%–8.9%(n=6). The precision and accuracy of this method can meet the requirement of the monitoring of residue limit of isocarbophos.