固相萃取-LC-MS/MS同时测定牛奶中7种β_2-受体激动剂

Solid Phase Extraction Coupled with Ultra Performance Liquid Chromatography-Mass Spectrometry for the Determination of 7 β_2-agonists in Milk

建立了牛奶中7种β2-受体激动剂残留量超高效液相色谱/串联质谱的分析方法。牛奶样品经40%甲醇溶液提取、乙酸锌溶液蛋白沉淀、HLB固相萃取柱净化后,以C_18为分析色谱柱,甲醇-0.1%甲酸溶液作为流动相进行梯度洗脱分离,采用多反应监测(MRM)模式测定。结果表明,7种β_2-受体激动剂在0.04μg/kg^4μg/kg的浓度范围内呈线性,其相关系数r^2大于0.998,定量限在0.01μg/kg^0.04μg/kg,加标回收率为66.8%~99.2%,相对标准偏差(RSD)范围为2.0%~15.8%。本方法灵敏度高,准确度好,对实际样品进行了测试分析,均获得了满意的结果。

A simple and inexpensive pretreatment procedure was developed for 7 β2-agonists （brombuterol, fonnoterol, mapenterol, mabuterol, ractopamine, clenbuterol, tulobuterol） in milk. The samples were extracted with 40 % methanol in water, and then Oasis HLB solid phase extraction （SPE） cartridges were used for cleanup. The analytes were quantified by ultra performance liquid chromatography coupled with electrospray ionisation tandem mass spectrometry （UPLC-ESI-MS/MS） operating in positive multiple-reaction mode （MRM）. Competent linearity was found for all target compounds with linear regression coefficients （R2） higher than 0.998. The limit of quantification ranged from 0.01 μg/kg to 0.04 μg/kg. Average recoveries spiked into raw milk were in the range from 66.8 % to 99.2 % with associated RSD values from 2.0 % to 15.8 % under the selected conditions. The method is rapid, cost-effective and can meet the requirements for identification and quantification of the β2-agonists in milk.