Comparison of XRF, TXRF, and ICP-MS Methods for Determination of Mercury in Face Creams

Abstract

Regulatory, media, and watchdog groups have identified numerous face cream products containing percent levels of mercury that far exceed the 1 ppm FDA regulatory limit. Mercury is added to these products to provide skin bleaching properties, and this poses a serious health risk to consumers. This study compares XRF, TXRF, and the more widely accepted ICP-MS methods for determination of mercury in face cream products. To identify contaminated products in a field setting, XRF is the preferred method, as it involves direct analysis of the sample, analysis times of a minute or less, and detection limits down to single ppm levels. XRF analysis gave quantitative results that compared well to those from ICP-MS for homogeneous products, but gave more variable results for products containing small crystals or chunks of inorganic mercury salts. More accurate results for these products requires preparation of a representative sample, microwave digestion, and TXRF or ICP-MS analysis. Given the continued production and distribution of mercury-containing face cream products, it is recommended that portable XRF be used to screen for such products or for accurate quantification of mercury in homogeneous products, and TXRF be used to determine the mercury content of more heterogeneous products. https://doi.org/10.21423/jrs-v09i2vrdoljak