Abstract: An analytical method for the determination of 4 steroid hormones in milk and milk power was developed by filtration solid phase extraction combined with ultra performance liquid chromatography-tandem mass spectrometry. Samples were extracted with acetonitrile, and purified on a PRiME HLB cartridge. Then the chromatographic separation was achieved using an Acquity BEH C18 column (2.1 mm × 100 mm, 2.5 μm) with a mobile phase consisting of water and acetonitrile. The compounds were ionized using an electrospray ionization source in the negative ion mode and quantitated by the internal standard method. The results showed that the calibration curves of all analytes had a good linear relationship in the concentration range of 0.2–100.0 ng/mL. The limits of detection and limits of quantitation were 0.4–2.0 and 0.8–4.0 μg/kg, respectively. The recoveries of the method were in range of 87.7%–110.8% with relative standard deviations (RSDs) of 0.85%–4.56% in milk and in range of 89.2%–107.4% with RSDs of 0.85%–4.56% in milk power. This method was proved to be rapid, sensitive, and useful for the quantification of 4 steroid hormones in milk and milk power samples.

Key words: high performance liquid chromatography-tandem mass spectrometry, steroid hormones, isotopic internal standard

摘要： 建立通过式固相萃取-高效液相色谱-串联质谱法同时测定牛乳和乳粉样品中4 种类固醇激素的方法，采用内标法定量，样品用乙腈提取，经PRiME HLB固相萃取小柱净化，采用Acquity BEH C18色谱柱（2.1 mm×100 mm，2.5 μm）分离，乙腈和水作为流动相，使用电喷雾离子源负离子模式检测。结果表明：4 种类固醇激素在质量浓度0.2～100.0 ng/mL范围内线性关系良好，检出限为0.4～2.0 μg/kg，定量限为0.8～4.0 μg/kg；在牛乳基质中加标回收率为87.7%～110.8%，相对标准偏差为0.85%～4.56%，在乳粉基质中加标回收率为89.2%～107.4%，相对标准偏差为1.22%～4.22%；该方法分析速度快、灵敏度高，可用于牛乳和乳粉中4 种类固醇激素的定性及定量分析。

关键词: 高效液相色谱-串联质谱法, 类固醇激素, 同位素内标法