An ICP-OES, TXRF, and EDXRF analysis of airborne particulate samples in an iron and steel smelter environment

Abstract

Elemental concentrations of air particulates collected by gravimetric method in a scrap iron and steel smelter industry were determined using a combination of four different techniques: total reflection X-ray fluorescence (TXRF), the conventional energy dispersive X-ray fluorescence (EDXRF), the modified (polarized) energy dispersive X-ray fluorescence ED(P)XRF, and the inductively coupled plasma optical emission spectroscopy (ICP-OES) analytical techniques. A number of elements were detected by all the techniques, some by one or two while some are better detected by a particular technique. The ICP-OES and TXRF techniques have low detection limits worth of consideration despite the risk of contamination possible during sample preparation. The techniques are observed to be adequate for analytes above K except for Br and Pb, which are significantly lost during digestion of samples. The Mo-target EDXRF, just like ICP-OES and TXRF, cannot detect elements below K but substitute well for them in the analysis of volatile elements like Br and Pb despite its higher detection limits for the said elements. The Mo-target EDXRF is also observed to be inadequate for rare earth elements with energies close to that of Mo as a result of possible poor resolution of the energy peaks. The ED(P)XRF is more adequate in the analysis of low Z elements as well as volatile ones. Where volatile elements like Cl, Br, and Pb and/or low Z elements are of primary interest, the use of techniques involving no elaborate sample preparation should be considered.

Keywords:

• EDXRF
• ED(P)XRF
• TXRF
• ICP-OES
• gravimetric
• energy peaks

Acknowledgment

The authors wish to acknowledge the support of the International Centre for Theoretical Physics (ICTP) under the framework of Training and Research in Italian Laboratories (TRIL) for the fellowship and scientific visit granted one of them (O.K. Owoade). The assistance of Prof. T.A. Kuku and Prof. Asubiojo of the Department of Electrical and Electronic Engineering and Chemistry, respectively, Obafemi Awolowo University, Ile-Ife, Nigeria, is also highly appreciated.