高效液相色谱法测定化妆品中的维生素C及其衍生物

Determination of the contents of vitamin C and its derivatives in cosmetics by high performance liquid chromatography

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.