固相萃取/高效液相色谱-串联质谱法同时检测多类食品中二甲基黄、二乙基黄含量

建立了豆干、辣椒酱、豆腐乳、腐竹和饼干等样品中二甲基黄和二乙基黄残留量的液相色谱-串联质谱分析方法。基于二甲基黄和二乙基黄的化学结构特性,采用乙腈溶液提取。提取液酸化后经Bond Elut Plexa PCX阳离子交换树脂固相萃取净化,吹干复溶后,使用反相C_(18)色谱柱分离,电喷雾串联四极杆质谱正离子化多反应监测(MRM)模式检测。二甲基黄和二乙基黄的方法定量下限均为0.50μg/kg。对5种不同基质样品进行二甲基黄和二乙基黄0.50,5.0,80μg/kg 3个浓度水平的加标回收实验,得到二甲基黄和二乙基黄的平均回收率分别为76.4%~93.0%和76.1%~92.4%;相对标准偏差分别为1.7%~6.3%和1.9%~7.4%,可以满足食品中二甲基黄和二乙基黄快速筛查和定量分析的要求。

Determination of Dimethyl Yellow and Diethyl Yellow in Variety of Foods by Solid Phase Extraction/Liquid Chromatography-Tandem Mass Spectrometry

A liquid chromatography-tandem mass spectrometric (LC-MS/MS) method was developed for the determination of dimethyl yellow and diethyl yellow in dried bean curd,chili sauce,tofuru,dried beancurd sticks and biscuit.In this study,based on the chemical structures of dimethyl yellow and diethyl yellow,the sample was first extracted using acetonitrile solution,and the extract was then acidified and purified with a Bond Elut Plexa PCX cation anion exchange cartridge.After drying and re-dissolvation,the analytes were separated by reverse phase LC using a C1s column,followed by detection using triple quadrupole mass spectrometry with positive electrospray ionization in multiple reaction monitoring(MRM) mode.The limits of quantitation were both 0.50 μg/kg.The recoveries of dimethyl yellow and diethyl yellow in food samples at three spiked levels of 0.50,5.0,80 μg/kg were in the range of 76.1％-93.0％ with relative standard deviations(RSDs) of 1.7％-7.4％.The method could meet the requirement for rapid screening and quantitative analysis of dimethyl yellow and diethyl yellow in foods.