液相色谱-串联质谱法检测牛奶中10种β-兴奋剂

Determination of 10 β-agonists in bovine milk by high performance liquid chromatography tandem mass spectrometry

建立了液相色谱-串联质谱同时检测牛奶中10种β-兴奋剂残留量的方法.样品经沉淀蛋白质,酸性水溶液提取, 提取液经Oasis MCX 固相萃取柱净化,LC/MS/MS方法测定.采用了Thermo Hypersil Gold (150×2.1 mm,5 μm) 色谱柱;5 mmol 乙酸铵水溶液-甲醇流动相,梯度洗脱.方法线性相关系数r均大于0.999.克伦特罗检出限为1.68 μg/kg,其余9种β-兴奋剂的检出限在0.146～0.203 μg/kg之间;克伦特罗定量限为3.37 μg/kg,其余9种β-兴奋剂的定量限在0.290～0.407 μg/kg之间.3个添加水平下,10种β-兴奋剂平均回收率在91% ～127%之间.

The method for the simultaneous determination of 10 β-agonists in milk was developed by high performance liquid chromatography-tandem mass spectrometry(HPLC-MS/MS).The sample was deproteinized by trichloroacetic acid,extracted with acidified water,then cleaned-up by an ion exchange solid phase extraction(SPE) column to obtain extract suitable for the analysis by HPLC-MS/MS.The separation was performed on a Thermo Hypersil Gold(150×2.1 mm,5 μm) column with gradient elution solvents of methanol-5 mmol ammonium acetate.The calibration curve was good linear between the peak area and the mass concentration of β-agonists with the correlation coefficient of 0.999.The limit of detection(LOD) of clenbuterol was 1.68 μg/kg,and the others nine β-agonists were between 0.146 to 0.203 μg/kg.The limit of quantification(LOQ) of clenbuterol was 3.37 μg/kg,and the others nine β-agonists were between 0.290 to 0.407 μg/kg.The average recoveries of 10 β-agonists were in the range from 91% to 127%.