X-ray fluorescent method for the analysis of trace elements in bio-materials with correction of the matrix effect.

Abstract

A method for correcting the matrix effect by measuring the intensity of fluorescent radiation and its absorption by the sample material in the same x-ray optical scheme is proposed. The use of a complex secondary Ag-Ge emitter as a primary radiation source provides a low detection limit for a wide range of chemical elements from Ca (Z = 20) to Mo (Z = 42) in the K-series and from Cd (Z = 48) to Bi (Z = 83) in the L-series. To measure the absorption, the radiation of an additional secondary emitter is used, of which the wavelengthcan be varied in the range from 0.633 to 3.38 Å, depending on the measured impurity. An example of determining the mass fraction of an impurity in a sample of unknown composition prepared from a mixture of state standard samples of aqueous solutions is given. The x-ray optical scheme was assembled on the basis of a portable Energy Dispersive X-ray Fluorescence(EDXRF) spectrometer. The method is designed to study materials with a base consisting of chemical elements with a low atomic number.