分子印迹固相萃取-超高效液相色谱-串联质谱法测定猪肉中5种β_2-受体激动剂残留

Determination of five β_2-agonist residues in pork by ultra-high performance liquid chromatography-tandem mass spectrometry with molecularly imprinted solid phase extraction

建立了一种分子印迹固相萃取-超高效液相色谱-串联质谱同时测定猪肉中5种β2-受体激动剂残留的方法。样品经过均质处理后置于乙酸铵/乙酸缓冲液中,加入内标物和β-葡萄糖醛酸酶/芳基硫酸酯酶,于55℃酶解2 h,调节溶液p H后通过分子印迹固相萃取柱净化,然后采用BEH C18色谱柱分离,以甲醇-0.1%（v/v）甲酸水溶液为流动相,采用梯度洗脱,在电喷雾正离子多反应监测模式下用内标法定量。检出限（LOD,S/N=3）和定量限（LOQ,S/N=10）分别为0.005～0.009μg/kg和0.015～0.025μg/kg。在0～10μg/kg范围内线性关系良好,相关系数≥0.993 3。添加水平为0.25、1、5μg/kg时,回收率为80.4%～92.9%,相对标准偏差为1.2%～6.3%。该方法具有灵敏度高、重复性好、回收率高等优点,适合同时进行多种β2-受体激动剂残留的测定。

An ultra-high performance liquid chromatography-tandem mass spectrometry （UPLC-MS/MS） method with molecularly imprinted solid phase extraction for the determina- tion of five β2-gonists residues in pork has been developed. After the sample preparation, the ammonium acetate/acetic acid buffer was added, followed by the internal standard and fl-glu- curonidase/arylsulfatase enzyme. The solution was incubated at 55℃ for 2 h. After adjusting the pH of the solution, it was purified by a molecularly imprinted solid phase extraction col- umn, then analyzed on a BEH C 18 column with methanol-0. 1% （v/v） formic acid aqueous solution as the mobile phases in gradient elution mode. The MS/MS analysis was in positive ion mode and multiple reaction monitoring mode. The analytes were quantified by the internal standard method. The limits of detection （ LODs, S/N= 3 ） and the limits of quantification （ LOQs, S/N= 10） were 0. 005-0.009μg/kg and 0. 015-0. 025 μg/kg, respectively. In the range of 0-10μg/kg, the correlation coefficients of linear calibration curves were not less than 0. 993 3. At the spiked levels of 0.25, 1.0 and 5.0 μg/kg, the recoveries were 80.4%-92.9% with the relative standard deviations of 1. 3%-6.3%. The method is of high sensitivity, good reproducibility, high recovery, and is useful for the simultaneous determination of multiple β2- agonists residues.