Objective To establish a method for determining phenoxyethanol,methyl 4-hydroxybenzoate,and propyl 4-hydroxy-benzoate in cosmetic products based on high-performance liquid chromatography(HPLC).Methods The samples were extracted by ultrasonic extraction with methanol and filtered by 0.45 μm PTFE filter membrane.High-performance liquid chromatography was per-formed on a ZORBAX SB-C18(150 mm×4.6 mm,5 µm)column with a mobile phase of methanol,acetonitrile,and 0.02 mol/L ammo-nium acetate(pH=4.0)for gradient elution,and a diode array detector was used for determination.Results Phenoxyethanol,methyl 4-hydroxybenzoate,and propyl 4-hydroxybenzoate showed a good linear relationship within the range of 242-20 000,14.6-4 000,and 6.6-4 000 mg/kg,respectively,with a correlation coefficient of＞0.999,a recovery rate of 90.4％-104％,and intra-and inter-day precisions of＜9.2％.The method was used in the proficiency test to determine the content of preservatives in cosmetics,and satisfac-tory results were obtained.Conclusion This method is simple,rapid,accurate,and stable and is suitable for the simultaneous deter-mination of phenoxyethanol,methyl 4-hydroxybenzoate,and propyl 4-hydroxybenzoate in cosmetics.
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