气相色谱法测定化妆品用原料聚乙烯醇中甲醇含量

建立了气相色谱法测定化妆品用原料聚乙烯醇(固体)中甲醇含量的方法。研究发现顶空法较蒸馏法、直接稀释法更适合用于测定化妆品用原料聚乙烯醇中甲醇含量。分别考察了溶剂和盐析剂对测定结果的影响,发现最佳的溶剂和盐析剂分别为10 m L水和0.5 g氯化钠。结果表明甲醇质量浓度在10~1 000 mg/L范围内线性关系良好,相关系数可达0.999 5,其回收率为92.6%~104.8%,相对标准偏差在1.2%~6.5%之间,检出限为5 mg/L。实验结果证明,该方法适用于化妆品用原料聚乙烯醇中甲醇含量的检测。

Determination of methanol in polyvinyl alcohol used in cosmetics by gas chromatography

A gas chromatography method was established for the determination of methanol in polyvinyl alcohol used in cosmetics. It is found that headspace method is more suitable than distillation method and direct dilution method to determine the methanol in polyvinyl alcohol used in cosmetics. The factors of solvent and salting-out agent were investigated and the appropriate conditions are 10 mL water and 0.5 g sodium chloride, respectively. Results indicate that the linear relationship of methanol in the range of 10-1 000 mg/L is good, with correlation coefficient of 0.999 5. The recoveries are ranged from 92.6% to 104.8%, while the relative standard deviations (RSD) are ranged from 1.2% to 6.5% and the detection limit is 5 mg/L. The results prove that this method is suitable for the determination of methanol in polyvinyl alcohol used in cosmetics.