Characterization of matrix effects for Pb L-shell energy dispersive X-ray fluorescence (EDXRF) in binary compounds of cadmium, copper, molybdenum, and zinc

Matrix effects on the intensity of characteristic L X-rays were investigated for X-ray fluorescence (XRF). Lead was selected to be the analyte and samples were prepared with powders of several elements. In XRF analysis, if the sample analyzed is a composite, the emitted characteristic X-rays of an element can be enhanced or weakened by emission from other elements. The weight fraction of Pb and accompanying element in the matrices prepared as tablets of PbCCu1-C, PbCZn1-C, PbCMo1-C and PbCCd1-C by powder metallurgy using pure powders were varied from 10% to 90% with 10% intervals. The K shell absorption edge of Cu and Zn is just below the characteristic L X-ray energies of Pb. However, Mo and Cd emits K X-rays with energies just above the L shell absorption edge of Pb when stimulated by primary photons. All samples were analyzed by XRF using a Si(Li) detector with good resolution and an Am-241 radioactive source to provide characteristic X-ray spectra. The intensities for L alpha, L beta, and L gamma X-rays were plotted as a function of the Pb concentration and the results were evaluated to characterize matrix enhancement and absorption upon L-shell X-rays.