气相色谱-质谱法测定动物性食品及生物材料中的克伦特罗残留

Determination of clenbuterol residues in animal foods and biological materials by gas chromatographic-mass spectrometric method

为监测食品中的克伦特罗残留 ,采用气质联机法测定动物性食品及生物材料中的克伦特罗残留。试样用高氯酸提取 ,经超声加热后 ,用异丙醇 +乙酸乙酯 (40 + 6 0 )萃取 ,萃取液以弱阳离子交换柱分离富集 ,用乙醇 +浓氨水 (98+ 2 )溶液洗脱并浓缩 ,经N ,O -双三甲基硅烷三氟乙酰胺(BSTFA)衍生 ,选择离子监测方式进行气相色谱质谱测定。以美托洛尔 (metoprolol)为内标 ,内标法定量。用猪肝和鸡肉为本底做了不同水平的回收实验 ,回收率在 4 9 6 %～ 82 4 %之间和 5 1 6 %～88 4 %之间 ,相对标准偏差 (RSD)在 13 8%～ 17 6 %之间。方法的定量限 (LOQ)为 0 5 μg kg。通过实验室协同性实验对动物肝脏、肌肉、尿液 ,人体尿液和血液进行测定 ,结果良好。本方法灵敏度高、特异性强 ,测定结果准确可靠 ,可用于动物性食品及生物材料中克伦特罗残留的确证检测。

A gas chromatographic-mass spectrometric method was developed for the determination of residues of clenbuterol in animal foods and biological materials. A three-step pretreatment is performed, involving sample extraction by a perchloric acid solution, liquid-liquid partition by mixture of isopropanol and ethyl acetate (40∶60) and purification on a LC-WCX column, and then clenbuterol was eluted from the column by 6 mL of ethnol: ammonium hydroxide (98∶2). The analyte was determined as the di-trimethylsilyl derivative and quantified against an internal standard of metoprolol. The recovery experiment was done with three clenbuterol levels in chicken and pork samples respectively, they are 0\^5 μg/kg, 1\^5 μg/kg,2\^5 μg/kg, and the results were from 49\^6% to 88\^4%, RSD was 13\^8%～19\^6%. The LOQ of the GC-MS method is 0\^5 μg/kg. We used the GC-MS method to determine clenbuterol residues in samples of chicken, pork, pork liver, urine and blood of poisoned persons, and got satisfactory results.