柱前衍生-高效液相色谱法测定化妆品中二甲基噁唑烷防腐剂

Determination of Dimethyl Oxazolidine Preservative in Cosmetics by Precolumn Derivation-High Performance Liquid Chromatography

建立了化妆品中二甲基噁唑烷防腐剂的柱前衍生-高效液相色谱(HPLC)分析方法。样品使用体积分数50%的乙腈溶液提取,9-芴甲基羰基氯柱前衍生,经RRHD-C18(2.1 mm×50 mm×1.7μm)色谱柱分离后,高效液相色谱-二极管阵列检测器检测,以保留时间和紫外吸收光谱定性,外标法定量。结果表明,二甲基噁唑烷衍生物在质量浓度1.00～20.0 mg/L范围内呈现良好的线性关系,相关系数均大于0.9990;方法检出限和定量限分别为6.50 mg/kg和20.0 mg/kg。样品平均加标回收率在83.4%～99.6%之间,日内和日间精密度(RSD,n=6)分别为2.1%～6.7%和5.0%～7.8%。该方法检出限、回收率和精密度满足化妆品中二甲基噁唑烷防腐剂的测定要求。

A precolumn derivation-high performance liquid chromatography (HPLC)method was established for the determination of dimethyl oxazolidine preservative in cosmetics.The samples were extracted with volume ratio of 50% acetonitrile solution,derivatized with 9-fluorenylmethoxycarbonyl chloride,separated by RRHD-C18(2.1mm×50mm×1.7μm) column and detected by high performance liquid chromatography-diode array detector.The retention time and UV absorption spectra were adopted for qualitation and an external standard method was used for quantification.Under the optimal conditions,the results showed that dimethyl oxazolidine had good linearity in the range of 1.00-20.0mg/L with the correlation coefficients more than 0.9990.The limit of detection and quantification of the method were 6.50mg/kg and 20.0mg/kg,respectively.The mean recoveries of three levels of spiked samples were ranged from 83.4% to 99.6% and the relative standard deviations for intra-day and inter-day were in the range of 2.1%-6.7%and 5.0%-7.8%,respectively.The method is accurate and reliable,which is suitable for the determination of dimethyl oxazolidine in cosmetics.