Simultaneous Determination of 11 Preservatives in Cosmetics by High-Performance Liquid Chromatography

Preservatives prevent the growth of microorganisms in foods, phar-maceuticals and cosmetics. There exist numerous restrictions regarding the maximum allowable levels of preservatives in cos-metics. We analyzed 11 regulated preservatives in commercial cos-metics and manufacturers need to analyze their products for quality control purposes. However, methods used in previous studies to date have been inadequate for use by public institutions and manufacturers. Therefore, an effective, scalable method for the analysis of preserva-tives in cosmetics is required. We developed a novel method for the simultaneous determination of 11 regulated preservatives in cosmetics by high-performance liquid chromatography (HPLC). We applied the samples to a C18 column in a simple mobile phase (5 mmol/L ammo-nium formate solution and acetonitrile) with gradient elution at a flow rate of 1.0 mL/min at a single wavelength (230 nm). The correlation coefficients of the calibration curves were>0.997. The percent recov-eries were 92.8–111.9 % and the relative standard deviations were <4.3 % (n5 6). The peak resolution for all preservatives was>1.9. Because of the simple conditions for isolation and complete separ-ation, the HPLC method can be effectively applied to the analysis of preservatives in commercially retailed cosmetics