Galchenko S. Influence of heavy metal trace concentrations on roentgen fluorescent spectra of bioassay.

The results of thorough investigation to the improvement of energy dispersive XRF- analysis of heavy metal trace concentrations in the material in order to introduce this method into medical practice are obtained and presented in thesis. The theoretical description and experimental measurement of backscattering peak (BP) in XRF spectrum was conducted. The response function of the X-ray detector system and instrument function of excitation system of spectrometer "Elvax" is obtained by the Monte Carlo method. It is found in experiment that the intensity of analyzed characteristic elements' lines has relation with the intensity of the BP. A compensation method of a negative influence of the roentgen exciting system instability effect on the results of XRF analysis is developed. Sensitivity increase coefficients of XRF analysis for heavy metals after their preconcentration by means of the original method of rapid thermal ashing of bioassays are calculated.