提出了用偏振能量色散-X射线荧光光谱法(XRFS)对塑料中REACH法规所高度关注的物质进行筛选。将塑料样品粉碎至直径小于2 mm的颗粒并置于模具中热压(250 ℃,30 min)成紧密的片块固体用于XRFS分析。在所选定的仪器工作条件下对样品中的铬、溴、铅、砷、锡及氯等6种元素进行了测定。测得其检出限(mg·kg-1)为:0.5(氯、砷),1.0(铬、铅),2.0(溴)和3.0(锡)。各元素测定值的相对标准偏差(n=12)在0.19%~7.2%范围内。应用此方法分析2个标准物质(EC680k及EC681k),6种元素的测定值与认定值一致。根据上述6种元素的测定值,用相应的换算系数计算出REACH法规所关注的7种物质(即六溴环十二烷、双三丁基氧化锡、五氧化二砷、三氧化二砷、三乙基砷酸酯、砷酸氢铅及重铬酸钠)的含量并进行了评估。

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.