Analysis of Hydroquinone and Mercury in Whitening Hand and Body Lotions Marketed through Offline and Online Channels Using Spectrophotometric Methods

Abstract

Whitening hand and body lotions are widely used cosmetic products, but unregulated products may contain prohibited depigmenting agents such as mercury and hydroquinone. This laboratory study screened eight lotion products marketed in Banda Aceh, comprising three products purchased through online channels and five products obtained from offline outlets. Mercury and hydroquinone were screened qualitatively using 0.5 N potassium iodide and 1% ferric chloride, respectively. Hydroquinone was assessed by UV-visible spectrophotometry, whereas mercury was measured by atomic absorption spectrophotometry. Hydroquinone was not detected in any sample. Samples 4, 5, 7, and 8 produced positive qualitative reactions for mercury. The corresponding calculated readings were 0.0085, 0.0084, 0.0030, and 0.0032 mg/L, respectively; however, all values were below the reported method detection limit (0.058 mg/L) and quantification limit (0.175 mg/L). Accordingly, these values should be interpreted as estimated signals rather than validated quantitative confirmation. The findings indicate a presumptive mercury-related safety concern in four products and support confirmatory testing with a more sensitive, fully validated method. Negative findings for the two analytes do not establish the overall safety of the products.