Comparison between elemental constituents of total suspended air particulate matter and ten-micron particulate matter using the X-ray fluorescence technique

Abstract

Characterization of air particulate and comparison between elemental constituents of total suspended particulate matters (TSP) and 10-micron particulate matters (PM-10) in ambient air at two industrial plants, in Rayong chemical industrial area, were performed using x-ray fluorescence technique. In this work, the elemental constituents in particulate for both types of dust, i.e. TSP and PM-10, were characterized into a group of major elements, such as Al, Si, Ca, Na, K, Mg, S and Fe, and a group of minor and trace elements, such as Pb, Br, Ni, Mn, Zn, Ti, and Cu. Concentrations of these elements were analyzed on WD Sequential X-ray Spectrometer PHILIPS 2400. In order to determine concentrations of all elements of interest, the addition method, i.e. self-standardization, was used. In this method, calibration curves were prepared by spiking atomic absorption grade solutions of that element onto the filters. The experimental results showed that for the group of major elements such as Al, Si, Ca, Mg, K, Na, Fe and S the average concentrations in TSP were about 6.6, 5.4, 5.43, 3.03, 5.31, 2.84, 5.07 and 2.54 times greater than in PM-10, respectively, and for the group minor and trace elements such as Mn and Ti, the concentrations in TSP were larger than in PM-10 by factors of 2.29 and 9.4, respectively. Variations of chemical composition caused by the spiking was tested by the peak-to-background method. The experimental results demonstrated that for the medium and heavy elements such as Zn and Pb having relatively high concentrations compared with other trace elements and for the light elements with high concentrations such as Al, Si and S, the effect of the matrix variations can cause the errors about 2 to 4% in concentration. For other elements, the errors caused by this effect were much less than the counting uncertainties and may be ignored.