Analysis of Propylene Glycol and 1, 3-Butylene Glycol in Cosmetics

Abstract

A rapid simple method was developed for the determination of propylene glycol (PG) and 1, 3-butylene glycol (1, 3-BG) in cosmetics including lotions, milk lotions, creams, cleansing foams and packs. The procedure is as follows: 1, 2-butylene glycol (1, 2-BG) (0.5w/v% ethanol solution) was added to samples as internal standard and it was mixed enoughly on ultrasonic bath. After the mixture was evaporated to dryness, the residue was extracted with methanol. Finally the extract obtained was analyzed by gas chromatography on 20% PEG-20M column. Three well separated sharp peaks, which correspond to PG, 1, 3-BG and 1, 2-BG respectively, were detected within 10min, Average recoveries of both PG and 1, 3-BG were greater than 97.8% and coefficients of variation were less than 2.1%. It was found that the proposed method was applicable to the quantitative determination of PG and 1, 3-BG in commercial cosmetics.