应用薄层色谱分离-分光光度法测定腮红和眼影中苏丹红的含量。试样中的苏丹红用正己烷超声提取,方法中用硅胶溶液和羧甲基纤维素钠溶液以一定比例混合后均匀涂在玻璃板上制成层析板,并用正己烷、丙酮及乙酸乙酯三者以100比6比8的比例配成的混合液作为展开剂进行薄层色谱分离。将试样溶液及苏丹红Ⅲ标准溶液同时点在层析板上,置于展开缸中,上行展开。根据比移值(Rf)与标准比较进行定性检测,然后刮取与标准相同水平位置的样品色斑和空白硅胶,分别用正己烷溶解后稀释并定容至5 mL,用1 cm石英吸收皿,于498 nm处测量标准及样品的吸光度。苏丹红Ⅲ、Ⅳ的线性范围分别为30 mg·L-1以内和5.0~30 mg·L-1。方法的检出限(3s/k)为0.05 mg·L-1。用苏丹红Ⅲ和Ⅳ标准溶液进行回收试验,测得回收率在93.7%~97.6%之间。

Sudan in blusher and eye shadow was separated by TLC and determined by spectrophotometry. The sample was extracted ultrasonically with n-hexane. A mixture of sodium cellulose carboxymethylate and silica gel with definite ratio was used as adsorbent. A mixture of n-hexan, acetone and ethyl acetate with the ratio of 100 to 6 to 8 was used as developing solvent. Definite amounts (in μL) of sample solution and standard solution of sudanⅢ were spotted simultaneously onto the chromatographic plate and developed upward with the developing solvent. Based on the values of Rf and comparison between the colored spots of sample and standard sudan solution, detection of sudanⅢ in the sample was performed. Then the colored spot of the sample together with spot of blank silica gel located at same level with the spot of the standard was scraped off the plate and dissolved in 5.0 mL of n-hexane. Absorbance of the solution was measured at 498 nm with 1 cm absorption cell, and content of sudan Ⅲ and Ⅳ in the sample was found from the calibration curve having the linearity ranges within 30 mg·L-1 and between 5.0 to 30 mg·L-1 respectively, with detection limit (3s/k) of 0.05 mg·L-1. Recovery was tested by addition of standard solution of sudanⅢ and Ⅳ, giving results of recovery ranged from 93.7% to 97.6%.