Preparation of Standard Samples for Use in XRFS Determination of Harmful Elements in Polypropylene Materials

A set of standard samples for use in XRFS determination of 5 harmful elements (i.e., Pb, Cd, Cr, Hg and Br) in polypropylene (PP) materials was prepared. At first, PP granules (or "mother granules") containing estimated high contents of the 5 target elements were prepared. Then the mother granules were mixed by stepwise dilution to prepare candidate PP samples containing the concentration levels. Finally, the standard samples which were suitable to be used in XRFS analysis, were perpared. ICP-AES and IC were used for determination of each element in the prepared standard samples. Homogeneity and stability of the prepared standard samples were determined by the F-test and t-test, giving values of F and t were all less than the critical values of F_0.05(14,135) and t_0.05(12), showing that the stability and homogeneity of the standard samples were satisfactory.