液相色谱-电喷雾串联质谱法检测鸡组织中5种聚醚类药物残留

建立了鸡组织中聚醚类药物多残留检测的高效液相色谱-电喷雾串联质谱方法。采用甲醇提取鸡组织中的拉沙洛菌素、盐霉素、莫能菌素、甲基盐霉素和马杜霉素,经硅胶柱净化,以乙腈(含0.1%甲酸)-0.1%甲酸水溶液(体积比为97:3)为流动相,Symmetry Shield RP18作为色谱分析柱,多反应监测(MRM)正离子扫描方式进行质谱检测。当5种聚醚类药物的添加水平为鸡肉0.1～1500 μg/kg、鸡肝0.2～4500 μg/kg时,平均回收率为71.6%～99.1%,日内测定的相对标准偏差(RSD)(n=5)为3.2%～10.7%,日间RSD(n=3)为4.6%～14.7%。2种鸡组织中5种聚醚类药物的定量限为0.1～1.0 μg/kg。该方法的灵敏度、准确度和精密度均符合兽药残留分析技术的要求,适用于鸡肉和鸡肝中5种聚醚类药物的多残留检测。

Determination of 5 polyether antibiotics in chicken tissues by liquid chromatography-electrospray ionization tandem mass spectrometry

A liquid chromatography-electrospray ionization tandem mass spectrometry (LC-ESI MS/MS) method for the determination of 5 polyether antibiotics (lasalocid, salinomycin, mon-ensin, narasin and maduramicin) in chicken tissues was developed. The polyether antibiotics were extracted from chicken tissues with methanol. The extract was evaporated to dry, and re-dissolved in hexane, then cleaned up on a Sep-Pak Silica solid-phase extraction cartridge. The target drugs were eluted with 6 mL methylene chloride-methanol (90= 10, v/v), and the eluate was collected and dried under a gentle stream of nitrogen gas, then the residue was dissolved with 1 mL acetonitrile (containing 0. 1% formic acid) and analyzed by LC-MS/MS. The LC sep-aration was performed on a Symmetry Shield reversed phase C18 bonded silica column with acetonitrile (containing 0. 1% formic acid) - 0. 1% formic acid (97:3, v/v) as mobile phase. The quantification was carried out by positive electrospray ionization and multiple reaction mo-nitoring (MRM) mode. The validation was carried out on spiked chicken muscle (spiked at 0. 1 -1 500 μg/kg) and chicken liver (spiked at 0. 2-4 500 μg/kg), the average recoveries of tar-get drugs ranged from 71. 6%-99. 1% with intra-day relative standard deviations (RSDs) of 3. 2%-10. 7% and inter-day RSDs of 4. 6%-14. 7%. The limits of quantification ( LOQs) in chicken muscle and liver were 0. 1 - 1. 0 μg/kg. The results demonstrated that the sensitivity, accuracy and precision of this method meet the requirements of veterinary drug residue analy-sis. The method is applicable to detect 5 polyether antibiotics in chicken muscle and liver.