β-环糊精修饰微乳毛细管电动色谱场放大-扫集法测定化妆品中的糖皮质激素

Determination of glucocorticoids in cosmetics by β-cyclodextrin-microemulsion electrokinetic chromatography with field-amplified and sweeping

将场放大和扫集两种在线富集技术联用,建立了以β-环糊精为添加剂的微乳毛细管电动色谱法分析测定化妆品中丁酸氢化可的松、醋酸泼尼松、醋酸泼尼松龙和醋酸氢化可的松4种糖皮质激素的方法。微乳毛细管电动色谱运行缓冲体系的组成为：2.4%（w/w）SDS,1.0%（w/w）正辛烷,5.6%（w/w）正丁醇,10 mmol/Lβ-环糊精,40 mmol/L磷酸盐缓冲液（pH 2.8）,进水8.2 k Pa×30 s,进样18.4 k Pa×80 s,分离电压为-20.2 kV,测量波长250 nm。在优化条件下,4种激素的富集倍数在497-586倍,在40-16 000μg/L范围内具有良好的线性范围。检出限（S/N=3）为12-20μg/L。应用此方法分析了化妆品样品,回收率在95%-105%,相对标准偏差均小于4.1%（n=5）。

Two on-line pre-concentration techniques including field-amplified and sweeping by β-cyclodextrin-microemulsion electrokinetic chromatography method were used to analyze hydrocortisone butyrate,hydrocortisone acetate,prednisolone acetate,hydrocortisone acetate in cosmetics.The microemulsion background running buffer was composed of 2.4% SDS,1.0% octane,5.6% butanol,10 mmol/L β-cyclodextrin,40 mmol/L phosphate buffer（ pH 2.8）.The conditions of water plug and sample injection were 8.2 kPa × 30 s and 18.4 kPa × 80 s,respectively.Separating voltage was- 20.2 k V.The detection wavelength was set at 250 nm.Under the optimum conditions,the enrichment factors ranged from 497-586.The calibration curves were linear at the concentration of 40 - 16 000 μg/L.The limit of detections were 12 - 20 μg/L（S/N = 3）.The developed method was used to analyze the corticosteroids in cosmetics.The recoverises ranged from 95% - 105%.The RSD values（n = 5） were less than 4.1%.