采用固相萃取-超高效液相色谱-串联质谱法测定了动物源食品中9种β2-受体激动剂的残留量。样品经与乙酸铵缓冲溶液(pH 5.2)匀浆后,加入β-葡萄糖醛酸甙酶及芳基硫酸酯酶混合溶液进行水解。将水解液离心,取上清液,通过PCX固相萃取柱净化。用氨水-甲醇(5+95)混合液淋洗萃取柱,洗脱液经吹氮蒸干,残留溶于流动相(B)中,所得溶液进行色谱分离。以Waters Atlantis dC18色谱柱为固定相,以不同体积比混合的乙腈(A)和含0.1%(体积分数)甲酸的5 mmol·L-1乙酸铵溶液(B)为流动相梯度洗脱,采用电喷雾正离子源模式检测。9种化合物的线性范围均在10.0 μg·L-1以内,测定下限(10S/N)均为0.5 μg·kg-1。在3个浓度水平上对方法进行回收试验,测得回收率在70.2%~120%之间,测定值的相对标准偏差(n=6)在3.8%~19%之间。

UHPLC-MS/MS with solid phase extraction (SPE) was applied to the determination of residual amounts of 9 β2-recepter agonists in food of animal origin. The sample was pulped with NH4OAc buffer solution (pH 5.2) and hydrolyzed with mixed solution of β-glucuronidase and aryl sulfatase. The hydrolyzate was centrifuged and the supernatant was purified by passing through PCX SPE column. The column was eluted with a mixture of aq.NH3-CH3OH (5+95). The eluate was evaporated to dryness by N2-blowing, and the residue was dissolved with the solution of mobile phase (B). The solution obtained was separated by using waters Atlantis dC18 column as stationary phase and mixtures of (A) acetonitrile and (B) 5 mmol·L-1 NH4OAc solution (containing 0.1% by volume of formic acid) in various ratios as mobile phase in the gradient elution. ESI+ was adopted in MS/MS. Linearity ranges of the 9 compounds were found in the same range within 10.0 μg·L-1 with the same lower limits of determination (10S/N) of 0.5 μg·kg-1. Tests for recovery were made at 3 concentration levels, giving values of recovery in the range of 70.2%-120% with RSD′s (n=6) in the range of 3.8%-19%.