Voltammetric analysis of hydroquinone in skin whitening cosmetic using ferrocene modified carbon paste electrode

Hydroquinone is the most effective whitening agent in skin whitening cosmetics. It has the ability to whiten the skin in a relatively shorter time compared to other whitening agents. However, based on the regulations of the Indonesian Food and Drug Administration (BPOM) and the United States Food and Drug Administration (FDA), the use of hydroquinone in whitening cosmetics is prohibited and is given zero tolerance. Therefore, it is the aim of this study to develop an alternative method to analyze the presence of hydroquinone in cosmetics that is easier, inexpensive, selective, and accurate. The result showed that the best composition of the electrode membrane which gave the best outcome was carbon: paraffin: ferrocene with each ratio of 6: 3: 1. The validity of the hydroquinone analysis method that uses carbon/ferrocene paste as the electrode shows good results with the working range of 0.20-10 µM, the sensitivity of 10.436 µA/µM, and detection limit of 0.06 µM. It is also selective in the analysis of a mixture of hydroquinone and arbutin. These electrodes have excellent accuracy in recovering hydroquinone analysis in cosmetic samples with an average recovery value of 99%. This electrode can also be used for arbutin analysis in cosmetics with an accuracy of 99%. This method is suitable to be used in skin whitening analysis, both hydroquinone and arbutin.