Fast and sensitive high performance liquid chromatography analysis of cosmetic creams for hydroquinone, phenol and six preservatives

A fast and sensitive HPLC method for analysis of cosmetic creams for hydroquinone, phenol and six preservatives has been developed. The influence of sample preparation conditions and the composition of the mobile phase and elution mode were investigated to optimize the separation of the eight studied components. Final conditions were 60% methanol and 40% water (v/v) extraction of the cosmetic creams. A C18 column (100 mm x 2.1 mm) was used as the separation column and the mobile phase consisted of methanol and 0.05 mol/L ammonium formate in water (pH = 3.0) with gradient elution. The results showed that complete separation of the eight studied components was achieved within 10 min, the linear ranges were 1.0-200 mu g/mL for phenol, 0.1-150 mu g/mL for sorbic acid, 2.0-200 mu g/mL for benzoic acid, 0.5-200 mu g/mL for hydroquinone, methyl paraben, ethyl paraben and propyl paraben, butyl paraben, and good linear correlation coefficient (>= 0.9997) were obtained, the detection limit was in the range of 0.05-1.0 mu g/mL, the average recovery was between 86.5% and 116.3%, and the relative standard deviation (RSD) was less than 5.0% (n = 6). The method is easy, fast and sensitive, it can be employed to analyze component residues in cosmetic creams especially in a quality control setting. (C) 2011 Elsevier B.V. All rights reserved,