QuEChERS-UPLC-MS/MS同时测定牛奶和奶粉中42种类固醇激素

摘要

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 chromatography-tandem 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 MgSO4and 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 C18column (2.1 mm × 100 mm, 1.7 μm) 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 0.5-500 μg/L with correlation coefficients larger than 0.99. The limits of quantitation (LOQs) ranged from 0.06-1.5 μg/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.%采用分散固相萃取QuEChERS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(Al2O3-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0.5~500 μg/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0.06~1.5 μg/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.