QuEChERS-UPLC-MS/MS同时测定牛奶和奶粉中42种类固醇激素

Simultaneous Determination of 42 Steroid Hormones in Milk and Milk Powder by QuEChERS Combined with UPLC-MS/MS

采用分散固相萃取Qu ECh ERS结合超高效液相色谱-串联质谱技术,研究同时测定牛奶和奶粉中42种类固醇激素残留量的样品前处理技术并优化检测条件,建立快速准确的检测方法。结果表明,样品用0.1%甲酸-乙腈提取,无水硫酸镁和氯化钠盐析,离心后经50 mg十八烷基硅烷(C18)、100 mg乙二胺-N-丙基硅烷(primary secondary amine,PSA)和300 mg中性氧化铝(Al_2O_3-N)净化,40%乙腈溶液复溶,使用Waters ACQUITY UPLC?BEH C18色谱柱分离,以乙腈和0.1%甲酸溶液为流动相进行梯度洗脱,采用电喷雾-正离子多反应监测模式,基质匹配外标法定量。在0.5～500μg/L的质量浓度范围内,42种类固醇激素的相关系数均大于0.99,该方法的检出限在0.06～1.5μg/kg之间。在牛奶和奶粉中分别进行3个水平添加实验(n=6),42种类固醇激素的回收率为70.3%～118.1%,相对标准偏差为0.6%～14.7%。本方法简单快速、准确度好、精密度高,适合于牛奶和奶粉中42种类固醇激素残留量的同时检测。

A modified quick,easy,cheap,effective,rugged and safe(QuEChERS)extraction method was developed for the simultaneous determination of 42 steroid hormones in milk and milk powder by ultra performance liquid chromatographytandem mass spectrometry(UPLC-MS/MS).Sample pretreatment was studied and the detection conditions were optimized to obtain a rapid and accurate method.The steroid hormones from samples were extracted with 0.1%formic acid in acetonitrile followed by a salting-out step with anhydrous MgSO4 and NaCl.After centrifugation,the supernatant was cleaned up with 50 mg of octadecylsilane(C18),100 mg of primary secondary amine(PSA),and 300 mg of aluminum oxide(Al2O3-N)and re-dissolved with 40%formic acid acetonitrile.The separation was performed on a Waters ACQUITY UPLC?BEH C18 column(2.1 mm×100 mm,1.7μm)with gradient elution using acetonitrile and water containing 0.1%formic acid as the mobile phase.The electrospray ionization mass spectrometry was operated in the positive mode using multiple reaction monitoring(MRM).The target compounds were quantified by the matrix-matched external standard method.Under the optimal conditions,the calibration curves of all the analytes were linear in the concentration range of 0.5–500μg/L with correlation coefficients larger than 0.99.The limits of quantitation(LOQs)ranged from 0.06–1.5μg/kg.The average recoveries for milk and milk powder at three spiked levels ranged from 70.3%–118.1%with relative standard deviations(RSDs)of 0.6%–14.7%.The method due to its simplicity,rapidity,high accuracy and high precision was suitable for the simultaneous detection of 42 steroid hormones in milk and milk powder.