Characterization of trace elements in size-segregated atmospheric particles: Insights from SEM-EDS analysis

Abstract

The use of scanning electron microscopy/energy-dispersive X-ray spectrometry (SEM-EDS) is an effective technique in analyzing the elemental contents of atmospheric particles and revealing their morphological structures. This study is to classify and quantify the elemental composition of PM10 by analyzing size-segregated collected particles using SEM-EDS in Istanbul region. This study compared the changes in trace elements in size segregated PM10 between the day of the Saharan dust event (SDE) day and the following dust-free day by determining them using SEMEDS. In SEM images, the differences in the morphological structures of aerosol particles from different sources adhering to the glass filter fibers were clearly seen. The effective directions of particle transport were determined using HYSPLIT air mass backward trajectories for the airflows for both days. After the SDE, the 7.76-fold decrease in PM10 concentration effectively demonstrates the effect on the transportation of desert dust to distant regions. Al, As, Ba, Ca, Cd, Cl, Cr, K, Mg, Na, Pb, S, Sb, Si, Ti, V and Zr were detected in the atmospheric particles by SEM-EDS. The SDE caused an increase in PM10 concentration in the region as well as effected on the elemental composition of different size of the particles especially Ca, Mg and Ti. In contrast, Cl, Cr, S and V were the dominant elements in the dust-free day samples, each originating from urban sources. This study provides the qualitative measurement of the elements collected on the filter by SEMEDS analysis in a short time with less experimental application.