摘要 |
The monoisotopic mass peak of an experimentally obtained mass spectrum (262) for a sample molecule is determined using a cross correlation method. A model spectrum (261), having a known monoisotopic peak position, is created based on knowledge of the sample molecule. A set of correlation values are calculated from intensity values IMODEL, IEXP for a selected mutual alignment between the spectra. A cross correlation analysis is used to find the best agreement between the model and the experimental mass spectrum, represented by a best value of a quality factor. The position of the monoisotopic peak of the model spectrum showing the best agreement with the experimental mass spectrum is selected as the best approximation of the monoisotopic peak of the experimental spectrum. Knowing the charge state of the analysed section of the mass spectrum it is possible to determine the monoisotopic mass of the sample molecule.
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