同位素内标-液质联用法测定鸡可食性组织中替米考星残留量

建立了鸡四种可食性组织中替米考星的液相色谱串联质谱内标法。样品经磷酸二氢钾缓冲液和乙腈提取后，C18固相萃取柱净化，以0.1%甲酸乙腈溶液和0.1%甲酸水为流动相，液相色谱串联质谱法测定，内标法定量。试验结果表明：鸡四种可食性组织中替米考星在1 μg/kg~100 μg/kg的浓度范围内呈线性关系，相关系数r大于0.99；替米考星在鸡四种可食性组织中的检测限为0.5 μg/kg，定量限为1 μg/kg；四种组织中替米考星添加浓度为1 μg/kg~4800 μg/kg时，批间平均回收率为94.6%~100.9%，批内、批间变异系数在1.11%-5.06%范围之间。本方法适用于鸡四种可食性组织中替米考星含量的测定。

Determination of Tilmicosin Residue in Edible Chicken Tissues by an Isotope-labeled Internal Standard Liquid Chromatography Tandem Mass Spectrometry

A liquid chromatography tandem mass spectrometry (LC-MS/MS) internal standard method for the detection of tilmicosin in four chicken edible tissues has been established.The samples were extracted with potassium dihydrogen phosphate buffer and acetonitrile, then cleaned up by C18 solid phase extraction columns, with 0.1% formic acid acetonitrile 0.1% formic acid water as the mobile phase, and was determined by liquid chromatography tandem mass spectrometry and quantified by internal standard method.The experimental results showed that there was a good linear relationship between the concentration range of 1 μg/kg to 100 μg/kg of tilmicosin in four chicken edible tissues, and the correlation coefficient r was greater than 0.99.The detection limit of tilmicosin in four chicken edible tissues is 0.5 μg/kg, and the quantitative limit is 1 μg/kg,when the concentration of timicosin in four tissues is 1-4800 μg/kg, the average batch-to-batch recovery rate is 94.6% -100.9%, the coefficient of variation within and between batches ranged from 1.11% to 5.06%.This method is suitable for the determination of tilmicosin content in four chicken edible tissues.