美白化妆品样品0.20 g经50%(体积分数,下同)甲醇溶液8 mL超声提取15 min后,用50%甲醇溶液定容至10 mL,离心后上清液经0.45 μm有机系滤膜过滤,采用高效液相色谱法同时测定其中12种美白功能物质的含量。以SHIMADZU Shim-pack GIS-C₁₈色谱柱为固定相,以不同体积比的甲醇-0.02 mol·L^-1磷酸二氢钾溶液(pH 6.00)的混合液为流动相进行梯度洗脱。结果表明,12种美白功能物质的质量浓度在一定范围内与对应的峰面积呈线性关系,检出限(3S/N)为0.000 1%~0.003 2%。按照标准加入法进行回收试验,回收率为71.6%~103%,测定值的相对标准偏差(n=6)小于8.0%。方法用于分析52批美白化妆品样品,烟酰胺的检出率最高(48%),检出量为0.004%~4.7%,另外还发现美白化妆品成分表存在标签标示混乱的现象,需引起重视。

The whitening cosmetic sample (0.20 g) was extracted by ultrasound in 8 mL of 50% (volume fraction, the same below) methanol solution for 15 min, and then the volume was made up to 10 mL with 50% methanol solution. After centrifugation, the supernatant was filtered with 0.45 μm organic filter membrane, in which 12 whitening functional substances were determined simultaneously by high performance liquid chromatography, using SHIMADZU Shim pack GIS-C₁₈ column as the stationary phase and the mixture of methanol and 0.02 mol·L^-1 potassium dihydrogen phosphate solution (pH 6.00) at different volume ratios as the mobile phase for gradient elution. As shown by the results, linear relationships between values of peak area and mass concentration of 12 whitening functional substances were found in definite ranges, with detection limits (3S/N) in the range of 0.000 1%-0.003 2%. Test for recovery was made by standard addition method, giving results in the range of 71.6%-103%, with RSDs (n=6) of the determined values less than 8.0%. This method was applied to the analysis of 52 whitening cosmetic samples, and the detection rate of nicotinamide was the highest (48%), with detection amounts of 0.004%-4.7%. In addition, it was also found that the labels of whitening cosmetics were confused, which should be attracted attention.