分散固相萃取-液相色谱-串联质谱法测定水果中19种酸性农药

Determination of 19 Acidic Pesticide Residues in Fruit by Dispersive Solid Phase Extraction and Liquid Chromatography-Tandem Mass Spectrometry

建立了同时检测葡萄、苹果和桔子等水果中2,4-滴等19种酸性农药的分散固相萃取-液相色谱-串联质谱（HPLC-MS/MS）方法。葡萄、苹果和桔子样品经乙酸-乙腈（1∶99,V/V）提取后,C18分散固相萃取净化,采用反相C18色谱柱分离。以0.1%甲酸和0.1%甲酸-乙腈溶液作为流动相进行梯度洗脱,采用多反应监测离子模式进行定性分析,基质标准曲线外标法进行定量分析,线性范围在0.01~0.2 mg/kg之间。在0.02,0.05和0.1 mg/kg添加水平下,19种酸性农药的回收率为70.3%～105.3%;相对标准偏差为0.37%～10.9%。本方法的定量限为0.005～0.02 mg/kg。

A method was developed for the determination of 19 acidic pesticides in fruit by dispersive solid phase extraction and liquid chromatography-tandem mass spectrometry （LC-MS/MS）. The 19 analytes were extracted from the fruit samples by acetic acid-acetonitrile （1：99, V/V）, and purified by dispersion solid phase extraction using C18 sorbent, and then analyzed by liquid chromatography-tandem mass spectrometry （LC-MS/MS）. The 19 analytes were then separated on a reversed phase column using a gradient elution program of aqueous solution containing 0.1% formic acid aqueous solution and 0.1% formic acid acetonitrile solution. Qualitative analysis was performed using multiple-reaction monitoring （MRM）. Matrix-matched calibrations were respectively used to quantify the residue concentrations. The recoveries were in the range of 70.3% -105. 3%, and the relative standard deviation （RSDs） were 0. 4- 10. 9% at 0 02 mg/kg, 0.05 mg/kg and 0.1 mg/kg three spiked levels for all analytes. The limits of quantification （LOQ） for all analytes were between 0.005 mg/kg and 0.02 mg/kg.