SYSTEM AND METHOD FOR ENHANCING CHARGE-STATE DETERMINATION IN ELECTROSPRAY MASS SPECTROMETRY

摘要

A method of mass spectrometry comprises ionizing a sample and obtaining mass spectral data relating to a plurality of ion detection events. The method then comprises applying match tolerances for mass to charge ratio (m/z), chromatographic retention time (tr), and ion mobility drift time (td), to the ion detection events in order to determine possible charge state connections. The method also comprises constructing a tentative isotope chain and querying ion detection events for a match to the tentative isotope chain. Once a tentative isotope chain has been constructed, the method further comprises determining a corresponding theoretical molecular mass and a corresponding theoretical isotopic distribution, querying one or more lookup tables and returning one or more parameters (New X, New X′, Δ New X′) related to the fractional mass to charge ratio (fm/z) and at least one of: ion mobility drift time (td); and nominal mass to charge ratio (Nm/z), of the ion detection events, and using the one or more parameters (New X, New X′, Δ New X′) to determine a unique charge state of the ions.