液相色谱-串联质谱法快速筛查马饲料中39种违禁药物

Simultaneous and Rapid Screening of 39 Prohibited Drugs in Horse Feed Using Liquid Chromatography-Tandem Mass Spectrometry

建立了同时快速筛查和确证马饲料中39种赛马违禁药物(包含抗心率失常类药物、抗惊厥类药物、止痉挛类药物、抗疟疾类药物、刺激剂、麻醉剂及大麻酚类药物)的液相色谱串联质谱(HPLC-MS/MS)分析方法。样品粉碎后分别经1 mmol/L HClO4溶液和酸化乙腈溶液提取,并通过混合型固相萃取柱净化。采用Agilent Zorbax SB(10.0 cm×2.1 mm i.d.,3.5μm)色谱柱,以0.4%甲酸水溶液和0.4%甲酸乙腈为流动相进行梯度洗脱,正离子多反应监测(MRM)模式下检测。方法对空白饲料3个加标水平下的平均回收率为58%～116%,相对标准偏差为1.6%～20.4%,各类药物线性良好(r2>0.99)。方法检出限(S/N≥3)和定量下限(S/N≥10)分别为0.2～25.0μg/kg和1.0～40.0μg/kg,其中超过67%药物的检出限在2.5μg/kg以下。实验结果表明,该方法分析时间短,灵敏度、精密度良好,适用于马饲料中上述几类药物的快速筛查和测定。

A high-throughput liquid chromatography-tandem mass spectrometric（LC-MS/MS） method was established for the simultaneous screening of 39 drugs for horse racing in horse feed prohibited by the International Equestrian Federation（IEF）,including opiod analgesics,antimalarial,antispasmodic,antiarrhythmic,anticonvulsant,stimulants and psychotropic drugs.Feed samples were deproteinated and extracted with 1 mmol/L HClO4 for the basic drugs and then with acidified acetonitrile in 20 min by sonication.The purification was performed by mix-mode solid-phase extraction（SPE） using multi-step loading of the extracts in weak acid and organic solutions and multi-elute with dichloromethane-isopropanol-concentrated aqueous ammonia（5 ∶4 ∶1） and acetonitrile.The extracts were separated on an Agilent Zorbax SB（10.0 cm×2.1 mm i.d.,3.5 μm） column with 0.4% formic acid and 0.4% formic acid acetonitrile solution as mobile phase by gradient elution and analyzed by LC-MS/MS under positive electro-spray ionization（ESI＋）mode with multiple reaction monitoring（MRM）mode.The method was validated with fortified samples at three levels and the results showed that the recoveries were in the range of 58%-116% with relative standard deviations of 1.6%-20.4%.The limits of detection（LODs,S/N≥3） and limits of quantitation（LOQs,S/N≥10）were 0.2-25.0 μg/kg and 1.0-40.0 μg/kg,respectively,among which more than 67% LODs of the drugs analyzed were below 2.5 μg/kg.This method has the advantages of saving time, good selectivity and sensitivity,and can be applied in the screening and confirmation of the drugs mentioned above in horse feed in routine analysis.