测定美白类化妆品中氢醌和苯酚的高效液相色谱法改进研究

Improvement on determination of hydroquinone and phenol in whitening cosmetics by HPLC

目的:对高效液相色谱法测定美白类化妆品中氢醌、苯酚的色谱条件进行优化。方法:以系统适用性为指标,比较了色谱柱类型、缓冲盐种类及流动相p H对氢醌、苯酚和化妆品样品分离效果的影响。对优化后色谱条件进行了方法学考察,并在此条件下对抽检的化妆品样品进行测定。结果:最优色谱条件:采用C_(18)(4.6 mm×250 mm,5μm)色谱柱,以10 mmol·L^(-1)磷酸二氢钾水溶液(磷酸调p H 3.5)-甲醇为流动相进行梯度洗脱,流速1mL·min^(-1),柱温25℃,检测波长280 nm,进样量5μL。在最优色谱条件下,氢醌质量浓度在0.4~40μg·mL^(-1)范围内,苯酚质量浓度在0.7~70μg·mL^(-1)范围内线性关系良好,相关系数分别为0.999 8和0.999 9,氢醌、苯酚检测限分别为0.000 5和0.001μg,定量限分别为0.002和0.003 5μg,精密度试验的RSD分别为0.4%~1.0%和0.3%~1.8%,回收率分别为98.4%~99.5%和100.4%~102.2%。对市售的美白祛斑类化妆品200批进行测定,在本文的样品处理方法下氢醌和苯酚的检出限分别为1和2μg·g^(-1),定量限分别为4和7μg·g^(-1),杂质峰和目标峰能够实现基线分离、峰形对称。结论:本法测定美白祛斑类化妆品中氢醌、苯酚含量的专属性好,可以为化妆品检验标准的改进提供参考。

Objective：To improve the chromatographic conditions for the determination of hydroquinone and phenol in whitening cosmetics by HPLC.Methods：Based on the system suitability, the factors including column type,buffer salt and p H of mobile phase on separation were studied.The method developed has been validated,and the cosmetic samples were determined under the optimized conditions.Results：The optimized chromatographic conditions were：C_（18）（4.6 mm×250 mm,5 μm）column was used with the mobile phase of 10 mmol·L（-1） monopotassium phosphate solution（adjusted to p H 3.5 with phosphoric acid）-methanol in a gradient elution programme at a flow rate of 1mL·min（-1）.The column temperature was set at 25 ℃,the determine wavelength was 280 nm,and injection volume was 5 μL.Under the optimized condition,hydroquinone and phenol got good liner relationship in the ranges of 0.4-40 μg·mL（-1） and 0.7-70 μg·mL（-1） with correlation coefficient of 0.999 8 and 0.999 9.LODs were 0.000 5 μg and 0.001 μg,and LOQs were 0.002 μg and 0.003 5 μg,respectively.The recoveries were 98.4%-99.5% and 100.4%（-1）02.2% with RSDs of 0.4%（-1）.0% and 0.3%（-1）.8%,respectively.200 batches of commercially available whitening cosmetics were analyzed,including astringent,emulsion,cream,and mask,etc.The limits of detection content of hydroquinone and phenol were 1 μg·g（-1） and 2 μg·g（-1）,and the limits of quantitation content were 4 μg·g（-1） and 7 μg·g（-1）,respectively.The target peak and the interference peak separated well with symmetrical shape.Conclusion：The improved method has good specificity for the determination of hydroquinone and phenol in whitening cosmetics,which can provide a reference for the improvement of cosmetics test.