A method, computer program and system to identify peaks generated by different physical ions in a solution including substances by analyzing mass and intensity coordinates of all peaks in a set of mass spectra measured with errors for a certain concentration c of the solution is here disclosed. The peaks in different mass spectra are associated to a same ion if they are sufficiently ‘close’ according to specific discrimination criteria that go beyond the proximity of mass values.A two stage process is applied, each stage consisting in applying the method to identify peaks in mass spectra. In stage 1, the method to identify peaks is applied on each set of mass spectra for each concentration. Resulting sequences of peaks, one peak in each spectrum, are associated to different ions. This output of stage 1 is converted into a set of virtual mass spectra having as virtual peaks, average peak coordinate values calculated on each sequence. The method to identify peaks is applied once on the virtual mass spectra and the resulting ion identification table refers to peak coordinates values associated to one ion for each concentration of the solution.