Method of standardless quantitative emission spectral analysis in criminalistic, expert legal, and forensic medical practice

Abstract

The traditional three-standard method is the principal quantitative method in applied emission spectrometry. It is simple, reliable, and has a fairly high accuracy. Moreover, in a number of cases the use of this method has rather serious limitations. Even in the case of analysis of metals whose composition is regulated by appropriate All-Union State Standards (GOST) and technical specifications (e.g., ferrous and nonferrous metals and their alloys) and is checked by standard methods, since the output of standard samples is limited as to number and assortment, many laboratories (especially peripheral laboratories) of expert institutions cannot carry out criminalistic research at the quantitative level. The problem of calibration becomes complicated in the analysis of untypical materials, for which standard samples are not produced in a centralized manner~ In-house preparation of standards encounters a number of difficulties due to the lack of the necessary equipment, pure materials, and reagents and their certification, especially in the preparation of metal standard samples and when the empirical composition of the objects studied varies over wide limits and is not known in advance, and the preparation of standard samples with the same composition, structure, and other characteristics as the objects under analysis becomes practically impossible.