气相色谱-质谱法测定肝脏组织中盐酸克伦特罗和盐酸莱克多巴胺

Determination of Residual Clenbuterol and Ractopamine in Animal Liver Tissues by Solid Phase Extraction with Gas Chromatography-Mass Spectrometry

建立了同时测定动物肝组织中盐酸克伦特罗和盐酸莱克多巴胺残留量的固相萃取-气相色谱-质谱分析方法。动物肝组织样品在碱化的条件下用乙酸乙酯和异丙醇混合溶剂提取，提取液浓缩后用乙酸乙酯溶解，然后再用稀盐酸反萃取去除脂肪，调pH值后经SCX固相萃取（SPE）柱净化，洗脱液经氮气吹干后经双三甲基硅基三氟乙酰氨（BSTFA）衍生，采用选择离子模式（盐酸克伦特罗：86、212、262、277，盐酸莱克多巴胺：163、192、234、250）进行测定，外标法定量。盐酸克伦特罗和盐酸莱克多巴胺的检出限分别为0．30和1．00μg／kg。盐酸克伦特罗添加浓度在1．0～5．0μg／kg范围内，添加回收率为77．4％～88．3％；相对标准偏差（RSD）为3．1％～5．1％；盐酸莱克多巴胺添加浓度在4．0～20．0μg／kg，添加回收率为69．8％～82．1％；相对标准偏差（RSD）为3．5％～4．9％；衍生物的峰面积与被测物浓度分别在0．003～1．00mg／L和0．012～4．00mg／L范围内呈良好的线性关系，线性回归系数均大于0．999。

A method was developed for determining residual clenbuterol and ractopamine in animal liver tissues using solid phase extraction （SPE） with gas chromatography-mass spectrometry （GC-MS）. Liver samples were extracted with mixed solvent of ethyl acetate and isopropyl alcohol under basic condition. The extract of clenbuterol and ractopamine was concentrated and dissolved in ethyl acetate, and then the ethyl acetate solution was stripped by diluted hydrochloric acid to remove the fat. After adjusting pH, the final extract was cleaned by SCX solid phase extraction （SPE） cartridge. The sample was added by bis（ trimethylsilyl） trifluoroacetamide（BSTFA） to derivate when eluent was dried by nitrogen. The selected ion mode （SIM） detection method （ions elected： 86,212,262,277 for clenbuterol and 163, 192,234,250 for ractopamine） was used. The detection limit of clenbuterol and ractopamine was 0. 30 μg/kg and 1.00 μg/kg, respectively. The recoveries in liver samples were 77.4% -88.3% for clenbuterol and 69.8% -82.1% for ractopamine, the relative standard deviations were 3.1% - 5.1% for clenbuterol and 3.5% - 4.9% for ractopamine. There was a good linear correlation （ the calibration coefficient is above 0. 999） between the peak areas and concentration of medicine in the range of 0. 003 -1.00 mg/L for clenbuterol and 0. 012 -4.00 mg/L for ractopamine.