Quantitative elemental mapping and characterization of the homogeneity of element distribution in polymer foils by microbeam x-ray fluorescence spectrometry

Microbeam XRF measurements of polymer foils of different thickness were per formed to compare the homogeneity of the distributions of element admixture s in plastics (polycarbonate foils). The measurements were performed with a n energy-dispersive x-ray fluorescence spectrometer utilizing capillary opt ics. The spatial resolution of the spectrometer set-up was about 30 mum. Th e distributions of Ti, Cr, Fe, Sr and Ba were investigated. The samples wer e prepared from plastic foils having different thickness ranging from about 90 to 2600 mum. For each sample, line scan measurements were carried out, each line scan consisting of 128 points. The local concentrations of elemen ts along the scanned path were calculated using the modified backscatter fu ndamental parameter method. The influence of the foil thickness on the elem ent distributions obtained was observed. It was found that of the investiga ted elements, barium had the most uneven distribution. Copyright (C) 2001 J ohn Wiley & Sons, Ltd.