DIRECT TOTAL-REFLECTION X-RAY-FLUORESCENCE TRACE-ELEMENT ANALYSIS OF ORGANIC MATRIX MATERIALS WITH A SEMIEMPIRICAL STANDARD

In this work we describe a method for trace element analysis in organi c matrix materials using direct irradiation of the sample in a total-r eflection X-ray fluorescence spectrometer. The method avoids: (i) the need to digest the organic material, (ii) the need to add an internal standard to the unknown specimens, and (iii) the need to weigh the tes t specimen. Quantification of unknowns is achieved with the scattered peak as the internal standard and a semiempirical computational model of a standard, instead of a real reference material, for spectrometer sensitivity calibration. Spectra of certified standard reference mater ials with an organic matrix, obtained with a monochromatized beam from an X-ray tube, were quantified, showing good agreement with nominal, certified or previously reported values for solid and liquid samples. (C) 1997 Elsevier Science B.V.