Multielement analysis of airborne dust by x-ray fluorescence spectrometry

An airborne dust sample collected on membrane filter is considered to be quite suitable for multielement analysis by X-ray fluorescence spectrometry, because it is usually a thin film and various trace metallic elements are uniformly distributed in a matrix of low atomic number elements, such as H, C, O, N and S. More than fifteen elements (Si, S, Cl, K, Ca, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn, Br, Rb, Sr, Mo, Pb) can be nondestructively determined for urban samples, and therefore the application of the X-ray fluorescence technique to the air pollution study will be much more popular in near future. The Japan Environment Agency is routinely making multielement analysis of monthly airborne dust samples collected at its several network stations by means of combined use of X-ray fluorescence and instrumental neutron activation analyses. The items described in this article are listed below. (1) Nature of airborne particulates and their size distribution. (2) Sampling by filter method, including samplers and filter media. (3) Size separation sampling. (4) Uniformity in samples. (5) General principle of X-ray fluorescence analysis of airborne dust and previous studies made by various researchers. (6) The method presently used in the Radiation Center of Osaka Prefecture-Energy dispersive X-ray fluorescence spectrometry using radioisotope excitation sources. (7) Multielement analysis by combined use of X-ray fluorescence analysis and instrumental neutron activation analysis. (8) Special application of X-ray fluorescence spectrometry-Simultaneous analysis of gaseous and particulate sulfur in the atmosphere by X-ray fluorescence spectrometry. (author)