Theoretical calculations of the influence of resonant Raman scattering on the quantification of XRF spectrochemical analysis

HÉCTOR JORGE SÁNCHEZ; MARÍA CECILIA VALENTINUZZI; JUAN JOSÉ LEANI

JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY

ROYAL SOC CHEMISTRY

Lugar: CAMBRIDGE; Año: 2012 vol. 27 p. 232 - 238

0267-9477

In this work we present theoretical calculations of the resonant Raman scattering contributions to the background of X-ray fluoerscence spectra. The main goal of the paper is to obtain a simple and reliable procedure to calculate the influence of RRS in spectrochemical analysis by x ray fluorescence including second order enhacement processes. In order to perform the calculations, the Shiraiwaand Fujino model was used to calculate the characteristic intensities of the different atomic processes involved. In the case of polychromatic excitation over a multi-element sampleof proximate atomic numbers, the calculations show that the RRS contribution is higher than Compton scattering but lower than coherent scattering, this last process being the most important source of background in the range of the fluorescent lines. The calculated effects of enhacements are rather low and have influence only on the lightest elements of the spectra. On the other hand, the RRS line interferes with fluorescent peaks in the case of monochromatic excitation when elements of proximate atomic numbers are analyzed. The model proposed here allows the analysis of the different sources of background, which contribute to a better understanding of the physical processes involved.