Determination of polyol humectants in cosmetics by GC method

GC method to determine content of 5 humectants including 1,2-propylene glycol,ethylene glycol,1,3-butanediol,diethylene glycol and glycerol in cosmetics simultaneously was established.The samples were extracted with methanol,then filtered and quantitatively analyzed by GC.The linear relationships between values of peak areas and mass concentration of 5 humectants were obtained,with linearity ranges of 10 μg/mL～1 200 μg/mL(for 1,2-propylene glycol and 1,3-butanediol),10 μg/mL～1 100 μg/mL(for ethylene glycol),10 μg/mL～1 000 μg/mL(for diethylene glycol) and 10 μg/mL～1 300 μg/mL(for glycerol).The correlation coefficient is 0.99.Using the proposed method in determination of 5 humectants in cosmetics,the average recovery achieves 93.6%～102.4%,and the RSD achieves 0.84%～1.75%(n=6).This method is simple,fast,reliable and accurate,and can be used for quality control with respect to the content of polyol humectants in cosmetic products.