化妆品中碱金属氯酸盐的检测方法研究

Development of Detection Method for Chlorates of Alkali Metals in Cosmetics

建立了薄层色谱法和电位滴定法联用测定化妆品中碱金属氯酸盐含量的方法。用薄层色谱将氯酸盐从其他卤酸盐中分离，与碘化物形成碘来鉴别碱金属的氯酸盐。通过鉴别试验后，在酸性条件下氯酸盐被锌粉还原，所形成的氯化物用硝酸银溶液进行电位滴定。试验结果表明：在0．03％～3．41％（以氯酸根离子计）的质量分数范围内，加标回收率为81．4％～105．2％，相对标准偏差（RSD）≤10％；定性检出限为0．03％（质量分数），定量检出限为0．10％（质量分数）。

A thin layer chromatography（TCL） ＆ potentiometric titration method was developed for the determination of chlorates of alkali metals in cosmetics. Chlorates were separated from other halates by thin layer chromatography and identified by the oxidation of iodide to form iodine. After identification, chlorate was reduced by zinc powder under acid conditions. The formed chloride was measured by potentiometric titration using a silver nitrate solution. The results showed that the recovery of the method was in the range of 81.4% to 105.2% under the concentration of 0.03% to 3.41% while being counted as chlorate ions（with relative standard deviation of not more than 10%）. Additionally, the detection and quantification limits were found to be 0. 03% and 0.10% respectively.