3-DIMENSIONAL DECONVOLUTION OF MULTIPLY CHARGED SPECTRA

A three-dimensional surface of signal vs molecular weight and adduct ion mass (H+, Na+, NH3+, etc) is introduced as an analysis tool for determining the mass of higher-molecular-weight compounds from their representations as a series of multiply charged peaks in a mass spectrum produced by electrospray ionization. This three-dimensional approach has distinct advantages over conventional two-dimensional analysis techniques with regard to detecting errors in the mass scale calibration, assessing the confidence level of a deconvoluted molecular-weight assignment and in analyzing complex multiply charged spectra of mixtures. Special techniques are introduced which allow analysis of multiply charged spectra; containing adduct ion mixtures, solvent molecules absorbed on the parent molecule and 'peaks' resulting from partial dissociation of the parent molecule.