Methodological Peculiarities of the Electron Probe X-Ray Microanalysis of Environmental Samples

A set of procedures was developed for the electron probe X-ray microanalysis (EPMA) of fish and animal bone tissues, solid snow sediments, and coal ashes. Various sample-preparation procedures and two variants of the optimum conditions for analytical measurements were considered. In calculating analyte concentrations, matrix effects were taken into account using ZAF methods and the function of generated X-ray distribution with depth, namely, by the PAP method and by adding a joint correction for absorption and atomic number within a biexponential (z) model. For EPMA of small fractions 1–5 m in size, an approach was proposed that takes into account the test sample size using an analytical expression. In calculations of concentrations for micron-sized particles, this approach can lower the relative deviation from the stoichiometric composition from 36.8% to 22.2%. In developing the procedures, the potentialities of the proposed technique were assessed and its metrological characteristics were determined.