Simultaneous Analysis of Hydroquinone and Retinoic Acid in Cosmetics by High Performance Liquid Chromatography

Abstract

The objective of this study was to develop a laboratory method for simultaneous analysis of 2 substances, hydroquinone and retinoic acid, in cosmetics. Analytical separation technique using high performance liquid chromatography. The stationary phase was a column packing with octadodecyl silane, size 4.6 x 250 mm, particle size 5 micron. Mobile phase using gradient system was a mixture of water and methanol, injection volume 10 microliters , determination by UV absorption at 295 and 353 nm for hydroquinone and retinoic acid, chart out at about 4 and 13 minutes, respectively. The analysis showed that the standard curve was linear in the concentration range from 20 to 100 micrograms per milliter. The correlation coefficient (r²) was 0.999. Limit of of detection for hydroquinone and retinoic acid were 10 and 20 ng, respectively; and the relative standard deviation (% RSD) of repeatability was less than 2.00. Thus, this method could be used to measure the types and amounts of hydroquinone and retinoic acid in cosmetic. These two substances could be analyzed at the same time with acceptable accuracy.