Chemical state analysis employing sub-natural linewidth resolution PIXE measurements of K alpha diagram lines

摘要

A high-energy resolution crystal spectrometer in Johansson geometry, which allows energy resolution below the natural linewidth of the K alpha diagram lines, was employed in the measurements of proton-induced K alpha x-ray emission spectra of titanium and sulfur pure and compound targets. The results demonstrate a clear dependence of the K alpha energy shifts on the chemical state of the element in the sample. This dependence permits the chemical state speciation of low-Z elements in an unknown sample by employing high-resolution PIXE measurements of the K alpha line. The potential of the technique in speciation studies is demonstrated in the case of an aerosol sample. The analysis of the K alpha line obtained from the high-energy resolution proton-induced S K alpha x-ray spectrum allowed the identification of sulfur in the aerosol sample as sulfate ([SO4](2-)). Copyright (c) 2005 John Wiley & Sons, Ltd.