Summarized criteria of chemical compounds identification using the chromatography-mass spectrometry

Abstract

Criteria of chemical identification used in target and non-target analysis during chromatography-mass spectrometry are reviewed. In both cases, the final criteria are comparable and have a close similarity of both chromatographic retention values (times or relative times) and mass spectra (individual ion masses, their relative peak intensities) of identified analytes and analytical standards. Similarity, usually, means maximum permissible deviations of those values from the corresponding standard values assigned to the known compounds. Identification criteria used are contained in the general guides on the chemical analysis issued by the international or national regulatory organizations. In the case of non-target identification, the analytes and the corresponding standards are unknown before the analysis. In the first stages of this kind of analysis, the candidate compounds are selected for the identification and then the candidate features are compared to those of the standard compounds with the use of the criteria suggested for the target analysis. During the selection of the candidates, one uses high resolution chromatography – tandem mass spectrometry, advanced computer methods of data processing and prediction, and performs searches in chemical data bases, collections of retention indices, and mass spectral libraries. The use of these techniques and workflows can be considered as a reliable condition of the candidates’ selection for the identification. The progress in non-target analysis depends on technique innovations in mass spectrometry, first, by improving the accuracy and reproducibility of ion masses. The development of computer technologies is no less important, which should ensure the emergence of more complete libraries of mass spectra and more accurate methods for predicting the mass spectrometric and chromatographic data. Keywords : chemical identification, mass spectrometry, chromatography, computers, quantitative criteria of identification DOI: http://dx.doi.org/10.15826/analitika.2020.24.3.003 B.L.Milman 1 , I.K. Zhurkovich 2 1 Institute of Experimental Medicine, ul. Akad. Pavlova 12, Saint Petersburg 197376, Russian Federation 2 Institute of Toxicology, ul. Bekhtereva 1, Saint Petersburg 192019, Russian Federation