高效液相色谱-串联质谱法测定黄瓜、草莓中乙嘧酚和二甲嘧酚

建立了黄瓜、草莓中高效液相色谱-串联质谱同时检测乙嘧酚和二甲嘧酚残留的方法。样品加入乙腈高速匀浆,提取液中加入无水MgSO4和NaCl,振荡离心后,取上清液经分散固相萃取净化,液相色谱-串联质谱电喷雾正离子扫描同时分析乙嘧酚和二甲嘧酚。以黄瓜、草莓为基质进行3档添加水平和5次重复性实验,结果表明,添加量为0.01～1 mg/kg,乙嘧酚和二甲嘧酚的平均回收率为77.6%～99.3%,RSD为1.1%～6.8%,乙嘧酚和二甲嘧酚的方法检测限均为2.0μg/kg,定量限分别为6.0和5.0μg/kg。

Determination of ethirimol and dimethirimol residues in cucumber and strawberry using high performance liquid chromatography-tandem mass spectrometry

An analytical method of ethirimol and dimethirimol residues in cucumber and strawberry by high performance liquid chromatography-tandem mass spectrometry(HPLC-MS/MS) was developed.Acetonitrile was added into the samples to extract ethirimol and dimethirimol residues.Then the mixture was high-speed homogenized and added with some anhydrous magnesium sulfate and sodium chloride.After shaking thoroughly and centrifugation,the upper layer was transferred and diluted for direct analysis.Then ethirimol and dimethirimol was simultaneously determined by HPLC-MS/MS with electricspray in positive ion scan mode.The fortified recoveries of ethirimol and dimethirimol in cucumber and strawberry matrices were 77.6%～99.3% at fortification levels ranging from 0.01 to 1 mg/kg.Relative standard deviations were 1.1%～6.8%.The limits of detection were 2.0 μg/kg for ethirimol and dimethirimol.The limits of quantification were 6.0 μg/kg for ethirimol and 5.0 μg/kg for dimethirimol.The method has the advantages of simplicity,good repeatability and sensitivity.