ИСТИНА

Laser-induced plasma is a short-lived emission source, and its geometry, temperature and electron density are rapidly changed. Although this provides an opportunity to select anappropriate condition for particular application, an interpretation of spectra of laser-induced plasma is still rather complicated task. Thus, anyone needs the tool for explanationof the experimental spectra and deducing the plasma parameters. We suggested analgorithm for relatively simple emission spectra modeling and line identification that can beuseful for LIBS applications as well as in other fields of analytical atomic spectrometry. Wefound that the accuracy of the experimental data fitting by the model can be achieved evenwith a regular grid of parameters (temperature, electron density, plasma mass). A fewdiscrepancies are primarily related to inhomogeneity of the laser-induced plasma and to theabsence of data on Stark broadening parameters. The developed algorithms are useful forchoice of the best analytical line under certain plasma and spectrometer parameters interms of: (i) spectral interferences, (ii) transmittance and (iii) intensity, for estimation ofdetection limits of trace elements in a known sample matrix, for detection of erroneousentries in databases, including transition probabilities and Stark parameters. Due to therough estimation of plasma parameters the modeling provides fruitful information to planLIBS studies (either plasma diagnostics or analytical studies) prior to experimentalmeasurement. Besides planning of LIBS studies, the developed tool can be useful for criticalevaluation of experimental data. In particular, we have clearly demonstrated that the C I247.856 nm line cannot provide any analytical information for carbon determination insteels. The modeling made possible re-calibration of a spectrum by its shape only. Evaluation of possible spectral interferences from weak lines of major constituents and strong lines of minor and trace elements was very helpful for sensitive determination of lightrare earth elements in geosamples, for which the lack of certified reference materials is stilla serious problem, with limit of detections below their Earth’s crustal abundances. Futuredevelopment of the tool is the consideration of plasma inhomogeneity to improve plasmadiagnostics by model spectra and the implementation of an optimization algorithm for multiparametric fitting.