Method computer program and system to analyze mass spectra

摘要

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.

主权项

1. A method performed on a computer system including a mass spectrometer and an ion identification engine to identify peaks generated by different physical ions in a solution including a certain concentration of at least one substance, the method comprising:
analyzing a solution including a concentration of a given chemical substance using the mass spectrometer to provide a plurality of mass spectrum data files; and employing the ion identification engine for:
reading coordinates of a peak from a first mass spectrum data file in the plurality of mass spectra data files;selecting from each mass spectrum data file other than the first mass spectrum data file, peak coordinates which are close to the read peak coordinates from the first mass spectrum, by computing a distance function qualifying a proximity between two peaks;determining a highest scored sequence of peaks comprising the read peak from the first mass spectrum and one selected peak from each other mass spectrum by computing a scoring function qualifying a likelihood that all peaks in the sequence have been generated by a same type of physical ion;storing the highest scored sequence only if a ratio of the highest scored sequence to a second highest scored sequence is above a limit ratio;reading coordinates of one other peak from the first mass spectrum data file and executing the preceding selecting, determining and storing steps until all the peaks from the mass spectrum are read, each of the resulting stored sequences containing peaks, one for each mass spectrum; andidentifying different physical ions in the solution based on the stored sequences, each of the scored sequences containing peaks generated by the same physical ion.