A confirmative method was developed to detect 24 sulfonamide residues in bovine milk simultaneously,which included sulfaguanidine,sulfanilamide,sulfisomidine,sulfacetamide,sulfadiazine,sulfathia-zole,sulfapyridine,etc,by ultra performance liquid chromatography coupled with electrospray ionization tandem mass spectrometry ( UPLC-ESI-MS/MS). In this method,the samples were extracted and purified. The UPLC separation was performed on an ACQUITY UPLCTM BEH C18 column (100 mm×2.1 mm i. d. ,1.7 μm) utilizing a gradient elution program of acetonitrile and water (containing 0.25% acetic acid) as the mobile phase. Identification and quantification were achieved by UPLC-ESI-MS/MS in positive mode and multiple reactions monitoring. Good linearities were observed in the range of 5-100 μg/kg with correlation coefficients above 0.99. The method was validated at 5,25 and 50μg/kg. The validation results were as follows, the average recoveries of 24 antibiotics ranged from 64. 2% to 110.9% with the relative standard deviations of 3. 2% - 13. 1 % . The detection limits of the method were 0.21 - 1.62μg/kg. The method could meet the requirements of both domestic and international legislation.%建立同时测定牛乳中24种磺胺类药物多残留的超高效液相色谱-电喷雾串联质谱 (UPLC-ESI-MS/MS)分析方法.样品经改良的QuEChERS技术提取和净化,采用ACQUITY UPLC~(TM) BEH C_(18)色谱柱(100 mm × 2.1 mm,1.7 μm ),0.25%乙酸水溶液和乙腈作为流动相进行梯度洗脱,超高效液相色谱分离,电喷雾离子源电离,正离子多反应监测模式进行定性和定量分析.24种药物在5～100 μg/kg浓度范围内线性良好,相关系数r均大于0.99,以5,25和50 μg/kg 3个浓度水平进行添加回收率实验,样品的平均回收率在64.2%～110 9%之间,相对标准偏差为3.2%～13.1%,方法的检出限为0.21～1.62 μg/kg.方法重现性好、灵敏度高、分析时间短、确证能力强,适用于牛乳中磺胺类药物多残留的确证检测.
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