Comparison of charge state determination methods for high resolution mass spectra

Since mass spectrometers measure mass/charge ratio rather than mass, determination of charge state is essential in order to determine mass. Charge state determination requires methods to accurately estimate the m/z difference between adjacent isotopic peaks. This is particularly difficult under conditions of low SNR and when isotopic clusters are poorly resolved. A new method for charge state determination using the Matched Filter approach that has been recently developed is presented and compared with the established methods under various conditions. The results show that the the Matched Filter method performs significantly better than the existing methods and has a particular advantage in cases involving overlapping isotopic distributions.