QuEChERS结合液相色谱-串联质谱法快速测定猪肉中多类兽药残留

采用改进的QuEChERS方法提取和净化猪肉样品，建立了同时测定磺胺类、磺胺类增效剂、β-受体激动剂、四环素类、喹诺酮类、金刚烷胺和性激素共7类35种兽药残留的液相色谱-串联质谱（LC-MS/MS）检测方法。样品经 Na₂EDTA（乙二胺四乙酸）-Mcllvaine缓冲液-2.5%（体积分数）乙酸乙腈溶液提取，提取液经盐析后取乙腈相，用氨基（NH₂）吸附剂分散固相萃取净化后，在电喷雾离子源正离子多反应监测（MRM）模式下进行测定，基质外标法定量。35种兽药在1.0～50.0 μg/L范围内线性关系良好，相关系数均大于0.996。在3个不同添加水平下的平均回收率为71.8%～113.5%，相对标准偏差为0.6%～9.8%（n=6），检出限和定量限分别为0.01～1.01 μg/kg和0.04～3.37 μg/kg。该方法操作简单，净化效果好，灵敏度高，适用于猪肉中兽药多残留的同时快速定性、定量分析。

Multi-residue determination of veterinary drugs in porcine muscle by QuEChERS and liquid chromatography-tandem mass spectrometry

A liquid chromatography-tandem mass spectrometric method with modified QuEChERS procedure for sample preparation was developed for the simultaneous determination of 7 classes of 35 veterinary drugs including sulfonamides, sulfonamide potentiators, beta-agonists, tetracyclines, amnatadine and sex hormones in porcine muscle. The drugs were extracted with 0.1 mol/L Na₂EDTA (ethylene diamine tetraacetic acid)-Mcllvaine buffer solution and acetonitrile containing 2.5% (v/v) acetic acid, and then the extracts were purified using dispersive-solid phase extraction with NH₂ sorbent, and finally analyzed by liquid chromatography-tandem mass spectrometry in multiple reaction monitoring mode via positive electrospray ionization. The correlation coefficients of the standard calibration curves for the 35 veterinary drugs were all above 0.996. The blank samples were spiked at three levels, and the average recoveries ranged from 71.8% to 113.5% with the relative standard deviations from 0.6% to 9.8% (n=6). The limits of detection and the limits of quantification were 0.01-1.01 μg/kg and 0.04-3.37 μg/kg respectively. The method developed is easy to operate, sensitive, with good purification effect and suitable for the determination of residues in porcine muscle.