串联固相萃取-液相色谱-串联质谱法测定食品中嘧啶胺类杀菌剂残留

建立了食品中嘧啶胺类杀菌剂嘧霉胺、嘧菌胺及嘧菌环胺残留的串联固相萃取-液相色谱-串联质谱(HPLC-MS/MS)检测方法。胡萝卜、辣椒等样品经乙酸乙酯提取,石墨化炭黑-弗罗里硅藻土串联固相萃取柱(ENVI-Carb-Florisil SPE)净化后,在HPLC-MS/MS仪上进行检测分析,采用外标法定量。质谱分析采用电喷雾电离,正离子扫描,多反应监测模式。结果表明,柱净化后无明显的基质效应,嘧霉胺、嘧菌胺和嘧菌环胺在1～20 μg/L内相关系数可达0.9990以上,具有良好的线性关系;每种杀菌剂选择两个离子对,其中一组用于定量: 嘧霉胺m/z 200.1/107.1,嘧菌胺m/z 224.0/106.0及嘧菌环胺m/z 226.0/108.1;另一组用于确证: 嘧霉胺m/z 200.1/183.1,嘧菌胺m/z 224.0/131.1和嘧菌环胺m/z 226.0/133.1。样品中添加0.1、0.5、1.0 μg/kg的标准品,其回收率为73.2%～98.7%,相对标准偏差(n=10)小于10%;嘧霉胺、嘧菌胺、嘧菌环胺的检出限(信噪比(S/N)=3)均为0.03 μg/kg;嘧霉胺、嘧菌胺、嘧菌环胺的定量限(S/N=10)均为0.1 μg/kg。实验结果表明,该方法提取效果好,具有良好的灵敏度、回收率和重复性。

Determination of fungicide anilinopyrimidine residues in food by series solid phase extraction-high performance liquid chromatography-tandem mass spectrometry

A high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) method was established for the determination of fungicide anilinopyrimidine residues including pyrimethanil, mepanipyrim, and cyprodinil in foodstuffs with series solid phase extraction (SPE). The food sample was first extracted with ethyl acetate, and then purified by an ENVI-Carb cartridge and a Florisil SPE cartridge. The analytes were determined by HPLC-MS/MS and quantified by external standard method. The mass spectrometric detection was operated with electrospray in positive ionization mode and the fungicide anilinopyrimidines were identified in multiple reaction monitoring (MRM) mode. The linear range of the method was 1~20 μg/L, with the correlation coefficient (r2) over 0.9990. The transitions of the precursor ions to two selected product ions were involved, in which one group for quantification were m/z 200.1/107.1 for pyrimethanil, m/z 224.0/106.0 for mepanipyrim and m/z 226.0/108.1 for cyprodinil, and the other group for identification were m/z 200.1/183.1 for pyrimethanil, m/z 224.0/131.1 for mepanipyrim and m/z 226.0/133.1 for cyprodinil, respectively. No significant matrix effect was found for spiked samples after the purification. The recoveries of the fungicide anilinopyrimidines spiked in food samples were 73.2%~98.7% at the spiked levels of 0.1, 0.5, 1.0 μg/kg. The relative standard deviations (RSDs) were less than 10%. The limits of detection (LODs) and limits of quantification (LOQs) were 0.03 μg/kg and 0.1 μg/kg for the three fungicides, respectively. The results showed that the proposed method is sensitive and accurate for the determination of fungicide anilinopyrimidines in foodstuffs. The method should be applicable for routine analysis of pyrimethanil, mepanipyrim, cyprodinil residues in foodstuffs.