Fundamental parameter approach to XRF spectroscopy measurements of arsenic in polyester resin skin phantoms

A fundamental parameter (FP) approach that explicitly incorporates the energy‐broadening response of the detector was developed. The ratio between Kα fluorescence peak area and the sum of coherently and incoherently scattered peak areas was used as an indicator of trace element concentration. The peak ratio was theoretically calculated using the FP method. The energy‐broadening response curve of the Si(Li) detector was estimated by matching the theoretical and experimental values of this ratio. The method was implemented for the analysis of the K‐shell x‐ray fluorescence (K‐XRF) spectra of six polyester resin samples corresponding to six different arsenic concentrations. A ¹⁰⁹Cd radioactive source provided the excitation radiation for spectra acquisition. The predicted detector energy resolution expressed as full width at half‐maximum (FWHM) for Fe Kα fluorescence peak (208 ± 5 eV at 6.4 keV) and As Kα fluorescence peak (222 ± 5 eV at 10.5 keV) were in agreement with the experimental measurements. Copyright © 2008 John Wiley & Sons, Ltd.