Assay of 1,4-dioxane in commercial cosmetic products by HPLC.

: The HPLC assay of 1,4-dioxane in a wide range of commercially available cosmetics containing polyethoxylated surfactants is described. After solid-phase extraction using Bakerbond CN- and Bakerbond C18-cartridges, samples were directly analysed on a LiChrospher CH-8 column with an acetonitrile water eluent and UV detection at 200 nm. Of the total cosmetic products investigated, 48% were found to contain 7.3-85.9 ppm of 1,4-dioxane.