气相色谱-串联质谱法测定蛋和蛋制品中氟虫腈及其代谢物残留量

建立了气相色谱-串联质谱法（GC-MS/MS）检测蛋和蛋制品中氟虫腈及其代谢物氟甲腈、氟虫腈硫醚和氟虫腈砜的残留量。蛋和蛋制品经水稀释，涡旋混合均匀；加入0.1%冰醋酸-乙腈溶液和氯化钠，经充分涡旋和振摇后，对样品进行超声提取、离心、提取上层清液；残渣用0.1%冰醋酸-乙腈溶液再提取1次，合并2次提取得到的上清液，浓缩；用乙腈溶解残渣，分散固相萃取（N-丙基乙二胺、石墨化碳黑和十八烷基硅烷）净化后，用气相色谱-串联质谱法测定，外标法定量；同时对提取溶剂、提取方式和分散固相萃取剂进行了优化。结果表明：4种化合物在2~100 μg/L范围内的线性关系良好，相关系数R²大于0.99，定量限为1.0 μg/kg。在1.0、2.0、4.0、20.0 μg/kg加标水平下，氟虫腈及其代谢物的回收率为72.0%~109.5%，相对标准偏差小于16.0%。该方法准确、简单、快速，可用于蛋及蛋制品中氟虫腈及其代谢物的同时测定。

Determination of Fipronil and Its Metabolite Residues in Eggs and Egg Products by GC-MS/MS

Fipronil and its metabolite residues (fipronil-desulfinyl, fipronil sulfide and fipronil sulfone) in eggs and egg products were detected by gas chromatography-tandem mass spectrometry (GC-MS/MS). The samples were diluted by water, and vortexed to mix uniformity. Then acetonitrile containing 0.1% acetic acid was added, followed by sodium chloride. After vortexing and shaking vigorously, the samples were ultrasonic extracted. Then the samples were centrifuged, and the supernatant layer was taken. Then residues were extracted by acetonitrile containing 0.1% acetic acid again. The supernatant layer of twice extraction was put together and evaporated to dryness. Then acetonitrile was added to dissolve the residue. This solution was cleaned up by dispersive solid phase extraction powder (primary secondary amine, graphitized carbon black and eighteen alkyl silane), then was analyzed by GC-MS/MS. The extraction solvent (ethyl acetate, acetone, acetonitrile and acetonitrile containing 0.1% glacial acetic acid) and extraction mode (shaking, vortexing ultrasonic and oscillation) were optimized. The optimization of dispersive-solid phase extraction powders was carried out by orthogonal experiment. The matrix effects of four compounds in eggs and egg products were definitely declined by the purification of dispersive-solid phase extraction. The quantification was carried out by external standard method of matrix calibration curve. The linear ranges of four compounds are 2-100 μg/L with the correlation coefficients more than 0.99. The limits of quantification of four compounds are 1.0 μg/kg. At four spiked concentration levels of 1.0, 2.0, 4.0 and 20.0 μg/kg, the recoveries are 72.0%-109.5% with the relative standard deviations (RSDs) less than 16.0%. This method is accurate, simple, quick, and suitable for simultaneous determination of fipronil and its metabolite residues in eggs and egg products.