液相色谱-串联质谱法测定蜂产品中吡虫啉及其3种代谢物

建立了蜂蜜和蜂花粉中吡虫啉及其代谢物吡虫啉烯烃、吡虫啉脲、6-氯烟酸的液相色谱-串联质谱(LC-MS/MS)检测方法.在QuEChERS方法基础上,针对目标物化学性质和样品杂质情况,对提取溶液的pH值、提取次数、净化材料等参数进行了优化.最终以5％甲酸-乙腈溶液提取两次,无水MgSO4、NaCl盐析分层,提取液经增强型脂类去除材料(EMR)净化,以LC-MS/MS进行测定,基质外标法进行定量分析.结果表明,蜂蜜和蜂花粉中吡虫啉、吡虫啉烯烃、吡虫啉脲、6-氯烟酸的平均加标回收率为86.0％～111.5％, 相对标准偏差在1.7％～9.6％之间, 检出限分别为0.20, 3.50, 0.40和14.00 μg/kg,定量限分别为0.60, 11.64, 1.20和45.00 μg/kg.本方法分析速度快、灵敏度高、重现性好,适用于蜂蜜和蜂花粉中吡虫啉及其3种代谢物的快速测定.

Determination of Imidacloprid and Its Three Metabolites in Honey and Bee Pollen by Liquid Chromatography-Tandem Mass Spectrometry

A method was developed for the determination of imidacloprid and its metabolites imidacloprid olefin, imidacloprid urea and 6-chloronicotinic acid in honey and bee pollen by liquid chromatography tandem mass spectrometry (LC-MS/MS). On the basis of typical QuEChERS method, the pH and times of extraction solvent, sorbents were optimized to ensure the extraction efficiency and the purification of extraction. Finally, the method was developed as follows: matrix was extracted with 5％ formic acid-acetonitrile twice, and the extraction was cleaned with enhanced matrix removal-lipid (EMR), detected with LC-MS/MS and quantified with external matrix standards. The results indicated that the average spiked recoveries of imidacloprid, imidacloprid olefin, imidacloprid urea and 6-chloronicotinic acid in honey and pollen samples were 86.0％-111.5％ with relative standard deviations (RSDs) of 1.7％-9.6％, the LODs were 0.20, 3.50, 0.40 and 14.00 μg/kg, and the LOQs were 0.60, 11.64, 1.20 and 45.00 μg/kg. The method was rapid and simple with high sensitivity and good reproducibility, and suitable for the determination of imidacloprid and its three metabolites residues in honey and bee pollen.