场放大进样-胶束毛细管电泳法测定化妆品中3种糖皮质激素

Determination of 3 Corticosteroids in Cosmetics by Field Amplified Sample Introduction-Micellar Capillary Electrophoresis

采用场放大进样-胶束毛细管电泳法对化妆品中氢化可的松、泼尼松和乙酸氢化可的松3种糖皮质激素进行了分离测定。电泳介质为0.20mmol.L-1硼砂缓冲溶液(pH 9.0),运行电压为-20kV,进样电压-20kV,进样时间45s,进水压力3kPa,进水时间20s,检测波长250nm。在优化试验条件下,氢化可的松、泼尼松和乙酸氢化可的松的检出限分别(3S/N)为0.015,0.017,0.017mg.L-1。应用此方法分析了化妆品样品,测得回收率在93.8%～107%之间,测定值的相对标准偏差(n=5)均小于5.1%。

Miceliar capillary electrophoresis with field amplified sample introduction was applied to the separation and determination of 3 corticosteroids, including hydrocortisone, prednisone and hydrocortisone acetate, in cosmetics. The optimized conditions were shown as follows： ① electrophoretic medium： 0.20 mmol·L^-1 borax buffer solution of pH 9.0; ② conveying voltage： --20 kV;③sample injection voltage： --20 kV;④ time of sample injection： 45 s;⑤pressure of water-intake： 3 kPa;⑥ time of water-intake： 20 s; ⑦detection wavelength： 250 nm. Values of detection limits （3S/N） for hydrocortisone, prednisone and hydrocortisone acetate found were 0. 015, 0. 017, 0. 017 mg·L^-1 respectively. The proposed method was used in the analysis of cosmetics sample, giving values of recovery in the range of 93. 8%--107% with RSD＇s （n=5） less than 5.1%.