Modeling of physical phenomena taking place in microanalysis can show limit
ations as well as possibilities of the method. Experimental microanalytical
data, particularly k-ratios, have been compared with calculated ones obtai
ned by mathematical simulation. The model uses the single scattering Monte
Carlo algorithm, where "Bethe cross section" is introduced for the descript
ion of inelastic events. Various ionization cross sections have been tested
to show their influence on the distribution functions Accuracy of the simu
lation has been tested at the boride and carbide datasets, comparing calcul
ated k-ratios with experimental data. They have revealed the uncertainty in
the mass absorption coefficients and their limitation to the quantitative
analysis of very light elements. Layered samples present the most crucial t
est for the model. Monte Carlo calculation results are compared with experi
mental data and commercial analytical programs. The paper has shown that th
e correction program based on first principles gives comparable accuracy wi
th analytical approaches for all cases. The progress in the quantitative an
alysis is conditioned by the progress in the theory as well as by the progr
ess in the accurate experimental determination of some physical parameters.