同位素稀释-气相色谱-串联质谱法测定猪肉中残留的4种β-受体激动剂

采用同位素稀释质谱法，结合固相萃取技术，建立了猪肉中克伦特罗、妥布特罗、溴布特罗、沙丁胺醇等4种β-受体激动剂残留量的气相色谱-串联质谱（GC-MS/MS）检测方法。向绞碎的猪肉中加入同位素内标克伦特罗-D₉、妥布特罗-D₉、溴布特罗-D₉，经β-盐酸葡萄糖醛苷酶/芳基硫酸酯酶酶解，醋酸铵缓冲溶液提取，高氯酸调pH，HLB-MCX固相萃取柱串联净化，用-N,O-双三甲基硅基三氟乙酰胺(BSTFA)+1%三甲基氯硅烷（TMCS）衍生化后，进行GC-MS/MS测定，使用内标法定量。结果表明，猪肉中添加2.5~35.0 μg/kg水平的β-受体激动剂，回收率为92.2%~112.8%，批内变异系数（CV）为1.0%~12.6%，批间变异系数（CV）为1.9%~13.2%。4种β-受体激动剂的线性范围为1.35~158.00 μg/L，相关系数R²≥0.999 7，方法最低检测限为0.13~0.40 μg/kg，最低定量限为0.40~1.27 μg/kg。该方法精密度好、灵敏度高，可简便、准确地测定猪肉中4种β-受体激动剂的残留量。

Multi-Residue Analysis of 4 β-Agonists in Pork Using Isotope Dilution Gas Chromatography-Tandem Mass Spectrometry

A method for multi-residue analysis of β-agonists, clenbuterol, brombuterol, tulobuterol, salbutamol in pork was established by using isotope dilution combined with gas chromatography-tandem mass spectrometry and based on solid phase extraction method. β-agonists, which are well-known for their ability to improve growth rate and reduce carcass fat when fed to farm animals, were often adulterated into animal feed illegally. However, this misuse had caused some severe accidental poisoning in humans. Therefore, the use of β-agonists in animal dreeding is banned in many countries, and the establishment of a high sensitivity, accurate of β-agonist detection method is very necessary. In this study, the homogenized samples were spiked with isotope-labeled internal standards clenbuterol-D₉, brombuterol-D₉, tulobuterol-D₉, enzymatically hydrolysed and extracted by acetic acid-buffer, adjusted pH by perchloric acid, and cleaned-up on HLB and MCX cartridge, and derivatized with N, O-bis (trimethylsilyl) trifluoro acetamide (BSTFA)+1% trimethylchlorosilane (TMCS), finally analyzed by GC-MS/MS. The experimental results showed that spiking with the 4 β-agonists at 2.5-35 μg/kg in blank samples, the recoveries were 92.2%-112.8%, and intra-day and inter-day coefficients were 1.0%-12.6% and 1.9%-13.2%, respectively. Using isotope as the internal standard for the determination of the material, it can effectively reduce the sample errors in the pretreatment, derivatization and instrumentation process. And under the certain conditions, 4 β-agonists can be effectively separated. The linear ranges of 4 β-agonists were 35-158.00 μg/L, the coefficient of correlation was not less than 0.999 7, detection limits were in the range of 0.13-0.4 μg/kg, and the quantitative limits were in the range of 0.40-1.27 μg/kg. The method is demonstrated to be suitable for the determination of clenbuterol, brombuterol, tulobuterol, salbutamol in pork.