Computational method and system for mass spectral analysis

A method for analyzing data from a mass spectrometer including obtaining calibrated mass spectral data involving at least one ion with its isotopes, by processing raw spectral data; obtaining library spectral data which has been processed to form calibrated library data; and performing a regression analysis, preferably using matrix operations, between the calibrated mass spectral data and the calibrated library data; and reporting at least one regression coefficient representative of a relative concentrations of a component in a sample which generated the raw spectral data. The invention is also directed to a mass spectrometer system that operates in accordance with the method, a data library of transformed mass spectra, and a method for producing the data library.