羊肉中多黏菌素A和多黏菌素B液相色谱—串联质谱检测方法的建立

目的] 建立一种液相色谱—串联质谱同步测定羊肉中多黏菌素A和多黏菌素B的方法。方法] 样品经10%三氯乙酸水溶液—乙腈溶液提取,WCX固相萃取柱净化,0.1%甲酸水溶液作为流动相进行梯度洗脱,流速0.30 mL/min,多反应监测（MRM）正离子模式扫描,用液相色谱—串联质谱仪检测,基质添加标准溶液外标法定量。结果] 多黏菌素A和多黏菌素B在5.0~110.0 μg/L浓度范围内呈良好线性关系,线性相关系数R>0.996,方法的定量限为0.50 μg/kg,3个添加水平的平均回收率为73.2%~115.6%,RSD≤10.0%。结论] 该方法高效、准确,适用于羊肉样品中多黏菌素A和多黏菌素B的定量及确证检测。

Development of a Liquid Chromatography-tandem Mass Spectrometry（LC-MS/MS）Method for Detection of Colistin A and Colistin B in Mutton

Objective] To develop a liquid chromatography-tandem mass spectrometry （LC-MS/MS） method for simultaneous detection of colistin A and colistin B in mutton. Method] The samples were extracted with 10% trichloroacetic acid aqueous solution-acetonitrile solution, and then the targets were purified and enriched with WCX solid phase extraction column. The targets were gradiently eluted using 0.1% formic acid aqueous solution as mobile phase with a flow rate of 0.3 mL/min. After screening by multiple reaction monitoring （MRM） under positive ion mode, the targets were detected by LC-MS/MS and were quantitatively determined by external standard method with addition of standard solution in matrix. Result] Colistin A and colistin B had a good linear relationship in the range of 5.0-110.0 μg/L, and the linear correlation coefficients were above 0.996. The limit of quantitation of the developed LC-MS/MS method was 0.50 μg/kg. At three adding levels, the average recoveries ranged from 73.2% to 115.6% with relative standard deviations （RSD） ≤10.0%. Conclusion] The developed LC-MS/MS method is highly efficient and accurate, and is applicable for quantitative and confirmatory determination of colistin A and colistin B in mutton samples.