Determination of Substances Highly Concerned by REACH Regulations in Plastics by Polarized Energy Dispersive X-Ray Fluorescence Spectrometry

Polarized energy dispersive X-ray fluorescence spectrometry was applied to the screening of the substances highly concerned by REACH regulations in plastics. The sample was crushed to granules of diameters less than 2 mm, and pressed into solid and dense flake in a mould at 250 ℃ for 30 min which was used for XRFS analysis. Six elements, i.e., Cr, Br, Pb, As, Sn and Cl, in the sample were determined under the optimized working conditions of the instrument. Values of detection limit found were (in mg·kg-1): 0.5 (for Cl and As), 1.0 (for Cr and Pb), 2.0 (for Br) and 3.0 (for Sn). Values of RSD′s (n=12) for the elements found were in the range of 0.19%-7.2%. Two CRM′s (EC680k and EC681k) were analyzed by the present method, giving results in consistency with the certified values. Based on the contents of the 6 elements found, amounts of the 7 substances highly concerned by REACH regulations, i.e., hexabromocyclododecane, bis(tributyl-tin) oxide, arsenic oxide, arsenous oxide, triethyl arsenate, lead hydrogen arsenate and sodium dichromate, were calculated by the conversion factors.