液相色谱-串联质谱法测定饲料中氢化可的松

Determination of hydrocortisone in feed by liquid chromatography-tandem mass spectrometry

中文关键词:  氢化可的松  液相色谱-串联质谱法  饲料  非法添加物

英文关键词:hydrocortisone  liquid chromatography-tandem mass spectrometry  feed  illegal additives

中文摘要:

      目的 建立液相色谱-串联质谱法(liquid chromatography-tandem mass spectrometry, LC-MS/MS)测定饲料中氢化可的松含量的分析方法。方法 饲料样品中的氢化可的松经甲醇提取、石墨化碳黑固相萃取柱结合氨基固相萃取柱净化, 配制基质匹配标准溶液, 外标法定量。色谱采用乙腈(A)和0.1%甲酸水溶液(B)作为流动相进行梯度洗脱, 质谱采用多反应检测模式(multiple reaction monitoring, MRM)对氢化可的松的定量离子和定性离子进行监测。结果 氢化可的松在5.0~500 ng/mL范围内线性良好, 相关系数r均大于0.9975; 方法定量限为5 μg/kg(配合饲料、浓缩饲料、精料补充料)和10 μg/kg(添加剂预混合饲料); 低中高不同浓度添加水平的回收率为77.0%~103.7%, 相对标准偏差小于10% (n=5)。结论 该方法操作简便、灵敏度高、准确度好, 适合饲料产品中非法添加物氢化可的松药物残留测定。

英文摘要:

      Objective To establish an analytical method for determining hydrocortisone content in feed by liquid chromatography-tandem mass spectrometry. Methods Hydrocortisone in feed samples was extracted with methanol, and purified by using a graphitized carbon black solid-phase extraction column combined with an amino solid-phase extraction column. A matrix-matching standard solution was prepared and quantified by external standard method. The chromatograms were gradient eluted with acetonitrile (A) and 0.1% formic acid in water (B) as mobile phases, and the mass spectrum was used to monitor the quantitative and qualitative ions of hydrocortisone in a multiple reaction monitoring. Results The linearities of hydrocortisone were good in the range of 5.0?500 ng/mL, and the correlation coefficient r were all greater than 0.9975. The limits of quantitation for the method were 5 μg/kg (compound feed, concentrated feed and concentrate supplement) and 10 μg/kg (additive premix feed). The recoveries were 77.0%?103.7% and the relative standard deviations were less than 10% (n=5) at different concentrations at low, medium and high levels. Conclusion This method is simple, sensitive and accurate, and is suitable for the determination of hydrocortisone residues in feed products.