材料期刊网

建立了化妆品中维生素 C及其3种衍生物（抗坏血酸葡糖苷（ AA-2G）、抗坏血酸磷酸酯镁（ AA-2P）、抗坏血酸乙基醚（ Only VCE））的高效液相色谱分析方法。化妆水、水乳液等含油脂较少的样品先采用30 mL 0.02 mol／L磷酸二氢钾溶液（ pH 3.0）直接提取，然后定容至50 mL；面膏等含油脂较高及凝胶类、啫喱类的样品先加入1.0 mL二氯甲烷分散均匀后再加25 mL 0.02 mol／L磷酸二氢钾溶液（ pH 3.0）提取。提取液在12000 r／min下离心后用0.22μm滤膜过滤。样品分析采用 YMC-Triart C18色谱柱，以0.02 mol／L磷酸二氢钾溶液（ pH 3.0）和甲醇溶液为流动相，梯度洗脱，流速为1.0 mL／min，柱温为25℃，使用二极管阵列检测器（ DAD）检测，检测波长为250 nm，外标法定量。结果显示：4种化合物在其线性范围内线性关系良好，相关系数（ r2）均大于0.9999；方法的定量限（以信噪比为10计）为0.04～0.08 g／kg；添加水平为0.25～5.0 g／kg时的回收率为95.6％～101.0％，相对标准偏差为0.62％～3.0％。该方法前处理简单、回收率高、精密度好，适用于化妆品中维生素 C及其衍生物的测定。

A method has established for the detection of vitamin C( VC ) and its derivatives ( ascorbyl glucoside, AA-2G;magnesium ascorbyl phosphate, AA-2P;ascorbic acid ethyl ether,Only VCE)in cosmetics by high performance liquid chromatography( HPLC). Low fat cosmetic samples such as make-up water and lotion were extracted directly with 30 mL 0. 02 mol/L potassium dihydrogen phosphate solution( pH 3. 0). High fat cosmetic samples such as face cream and gel were well dispersed with 1. 0 mL dichloromethane first,then extracted with 25 mL 0. 02 mol/L potassium dihydrogen phosphate solution( pH 3. 0). The sample solution was centrifuged with a speed of 12 000 r/min,then filtered through a 0. 22 μm syringe filter. The fil-trate was analyzed on a column of YMC-Triart C18(250 mm×4. 6 mm,5 μm)using 0. 02 mol/L potassium dihydrogen phosphate solution( pH 3. 0)and methanol as mobile phases with a flow rate of 1. 0 mL/min. The temperature of the column was 25 ℃ and the detection wavelength was 250 nm. The standard working curves of the four analytes had good linear relationship(r2>0. 999 9). The detection limits of the four analytes were 0. 04-0. 08 g/kg(S/N=10). The recov-eries were 95. 6%-101. 0% with the relative standard deviations of 0. 62%-3. 0% at the spiked levels of 0. 25-5. 0 g/kg. This method is a simple,rapid,exact and reliable for the determina-tion of the contents of vitamin C and its derivatives in cosmetics.