X-ray diffraction analysis of atmospheric dust using low-background supports

Mineralogical analyses of atmospheric particulates collected on filter medi a have been performed by X-ray diffraction (XRD). The low peak intensity/ba ckground ratio commonly found in the XRD analysis of dust deposited on filt ers is improved by the use of other different supporting media. Membrane fi lters with atmospheric dust have been directly analyzed by X-ray diffractio n and then extracted from filter and deposited on three different substrate s for analysis: glass slides, silver membrane filters and silicon plates cu t parallel to (510) crystalline planes. The same procedures were carried ou t using a clay mineral standard (illite, <2<mu>m). The use of low-backgroun d silicon (510) plates offers the best results, improving net peak intensit ies and peak/background ratio. (C) 2001 Elsevier Science Ltd. All rights re served.