采用高效液相色谱-串联质谱法测定了猪肉中9种β-受体激动剂的残留量.样品经β-葡萄糖醛苷酶/芳基硫酸酯酶酶解后加入高氯酸沉淀蛋白并离心,取上清液过PCX阳离子固相萃取小柱净化,用氨水-甲醇(5+95)混合液洗脱,氮气吹干后用乙腈定容至1 mL.以CAPCELL PAK CR色谱柱为分离柱,以10 mmol·L-1乙酸铵溶液-乙腈(55+45)混合溶液(含体积分数为0.1%的甲酸)为流动相进行洗脱,采用电喷雾正离子源及选择反应监测模式进行测定,内标法进行定量.9种β-受体激动剂的质量浓度在4.00~100 μg·L-1范围内与其峰面积呈线性关系,方法的检出限(3S/N)在0.09~0.50 μg·L-1之间.对空白样品进行加标回收试验,回收率在83.2%~102%之间,测定值的相对标准偏差(n=6)在5.0%~12%之间.

The HPLC-MS/MS was used to determine 9 β2-agonists residuals in pork. The sample was hydrolyzed by β-glucuronidase/aryl sulfatase. The protein was precipitated with perchloric acid and removed by centrifugation. The supernatant was purified by PCX solid phase extraction column with a mixture of ammonia and methanol (5+95) as eluent. The eluate was dried under N2 stream,then the residue was dissolved with 1 mL acetonitrile. The CAPCELL PAK CR column was used as stationary phase and the mixture (contain 0.1% φ) of 10 mmol·L-1 ammonium acetate and acetonitrile (55+45) was used as mobile phase for elution. ESI+ and SRM were adopted in MS/MS. The linear relationship between the peak area and the mass concentration of the 9 β2-agonists was in the range of 4.00-100 μg·L-1,with detection limits (3S/N) in the range of 0.09-0.50 μg·L-1. Recovery rates measured by standard addition method were in the range of 83.2%-102% with RSD′s (n=6) in the range of 5.0%-12%.