Method for identification of the monoisotopic mass of species of molecules

Method for identification of the monoisotopic mass or a parameter correlated to the mass of the isotopes of the isotope distribution of at least one species of molecules contained in a sample and/or originated from a sample by at least an ionization process comprising the following steps:

• (i) measuring a mass spectrum of the sample with a mass spectrometer
• (ii) deducing for each of the at least one species of molecules contained in the sample and/or originated from the sample from the measured mass spectrum at least two isotope distributions of their ions having a specific charge z by deducing a charge score csP1(z1) of a first isotope distribution of a measured peak P1 of the mass spectrum by multiplication of at least three of the four sub charge scores a first Patterson function sub charge score csP_PX(z1), an first accuracy score sub charge score csAS_PX(z1), an first autocorrelation function sub charge score csAC_PX(z1) and a first isotope score sub charge score csIS_PX(z1) and a charge score csP1(z2) of the a second isotope distribution of the measured peak P2 of the mass spectrum by multiplication of at least three of the four sub charge scores a second Patterson function sub charge score CSP_PX(z2), a second accuracy score sub charge score csAS_PX(z2), a second autocorrelation function sub charge score csAC_PX(z2) and a second isotope score sub charge score csIS_PX(z2),
• (iii) deducing from the at least two deduced isotope distributions of the ions of each of the at least one species of molecules contained in the sample and/or originated from the sample the monoisotopic mass or a parameter correlated to the mass of the isotopes of the isotope distributions of the species of molecules.