Assesment on hydroquinone in selected cosmetic cream and toner via high performance liquid chromatography and ultra-violet visible detector spectrometry

Hydroquinone (HQ) is a whitening component in many cosmetic products, but only allowable at a very low concentration. The abuse of HQ will damage the skin and the sensitive area on the face. Due to this, many countries including Malaysia prohibited the use of HQ. However, the increasing number of whitening products in the market makes HQ suspiciously available. Thus, in this study, two quantitative methods of determining the HQ concentration were used. They were namely High Performance Liquid Chromatography (HPLC) and Ultra-Violet Visible Detector Spectrometry (UVDS). In the HPLC analysis, three types of mobile phase were used to separate three types of whitening products. The best mobile phase ratio was 20:80 v/v (methanol: water) due to the sharp peak of HQ and acceptable retention time (5.3 min). From the UVDS analysis, the measured HQ was found comparable to the HPLC results. Both methods were able to detect HQ lower than the permissible concentration. The HQ was also found to be stable for analysis in the same day and different days