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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 wavelength can 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. [ABSTRACT FROM AUTHOR]

The classical approach of James and Brindley for determining the shielding of a nucleus by electrons from the atomic form factor of the scattering of x rays is generalized for atoms in a bound state. It is shown that for chemical elements with atomic number Z < 10, the ratio of the peaks of coherent IR and incoherent IC scattering in the range of (sin θ)/λ from 0.7 to 2.0 Å−1 is determined by the form factor of scattering by internal electrons of the (1, 0) level. For each atom in a multicomponent system, there is only one adjustable parameter—the effective charge Z* = (Z − s), which characterizes the shielding of the nucleus by electrons. Fitting the dependence IR/IC ((sin θ)/λ) allows you to determine Z* for each free or bound atom and calculate its electronegativity. The values of the electronegativity of lithium, boron, carbon, oxygen, and fluorine in compounds with different types of chemical bonds are analyzed. [ABSTRACT FROM AUTHOR]

A generalization of the Compton method for determining elements with a low atomic number Z from 1 (H) to 9 (F) by the ratio ICIR of the intensities of incoherent (Compton) and coherent (Rayleigh) scattering is proposed. The generalization takes into account not only the dependence of this ratio on the effective atomic number of the scatterer material but also the momentum transfer variable x = sinθλ. The new method is based on the application of calibration function of ICIR=gZ,x obtained by measuring scattering spectra at two values of x1= 0.831 Å−1 and x2= 1.297 Å−1 with a WDXRF spectrometer. The elemental atomic numbers and their concentrations of binary compounds with unknown compositions are determined by the solution of a system of linear equations. Coefficients of the equations are calculated from the measured ICIR ratios for the test sample and the regularization solution for the corresponding calibration. The experiments have been carried out for standard samples of single‐component, binary and triple stoichiometric compounds based on H, Li, Be, B, C, O and F. The identification of these elements was found to be possible in the absence of a relationship between the positions of scattering peaks and the composition of the sample, and a qualitative and quantitative analysis of the composition of the material was carried out as part of the solution of a single inverse problem. [ABSTRACT FROM AUTHOR]