高效液相色谱-串联质谱法测定食品和饲料中醋酸甲孕酮

Determination of medroxyprogesterone acetate in foods and feeds by high performance liquid chromatography-tandem mass spectrometry

目的：利用液相色谱-串联质谱联用仪,建立食品和饲料中醋酸甲孕酮的检测方法,并用来调查醋酸甲孕酮在食品和饲料中的污染情况。方法：样品加醋酸缓冲溶液均质,加酶溶液酶解后,再加甲醇超声提取。用叔丁基甲醚萃取2次,萃取液经反相固相萃取柱净化;以乙腈-水为流动相,经反相C18柱分离后进行LC/MS/MS分析。质谱采用正离子扫描模式,离子源为ESI（＋）,定量检测方式为多反应监测（MRM）方式,利用保留时间和碎片信号比值判断定性结果。结果：醋酸甲孕酮线性相关系数r为0.9983,变异系数在1.1%~5.8%之间,高、中、低不同水平的加标回收率在85.9%~97.2%之间。检测了56份肉类食品和13份饲料样品,结果显示食品中未检出醋酸甲孕酮,饲料中有3份检出少量的醋酸甲孕酮,含量在0.21~0.91μg/kg之间。结论：该方法简便快速,精密度较高,重现性较好,可应用于食品和饲料中醋酸甲孕酮的测定。饲料中检出少量的醋酸甲孕酮有待进一步确证和寻找来源。

Objective：To establish a method to determinate medroxyprogesterone acetate（MPA）,and to study the MPA pollution in food and feed.Methods：Samples were homogenized in acetate buffer and decomposed under enzyme existing,and placed in super-sonic instrument for 5 minutes to distilled MPA,and then extracted with tert-butyl methyl ether.Then they were cleaned up through solid-phase extraction column.With the aid of d8-progesterone internal standard,a high performance liquid chromatography-tandem mass spectrometric method was used to determine MPA.Mobile phase was acetonitrile and water.Analyte identification and quantification were performed using multiple reaction monitoring（MRM） and electrospray ionization in positive mode.Quantitative results were based on MRM using isotope internal standard technique.Results：The correlation coefficients were above 0.9983,the relative standard deviation（RSD） were ranged from 1.1% to 5.8% and the recoveries were 85.9%～97.2%.56 meat foods and 13 feeds in Shenzhen were analyzed.3 feeds were proved to contain a small quantity of MPA and the concentration was changed from 0.21 μg/kg to 0.91 μg/kg.Conclusion：The method is simple,effective,and accurate.It can be applied to the determination of MPA in foods and feeds.MPA of feeds should be studied more carefully.