Mass spectrometric method and MALDI-TOF mass spectrometer

摘要

A method of normalising the spectral intensities of mass spectrometry data comprises (i) forming an intensity profile for each individual spectrum, wherein the intensity profile describes the statistical distribution of intensity values within different mass ranges; (ii) forming an average reference profile for an ensemble of spectra; and (iii) transforming the individual spectra such that their intensity profiles correspond to the reference profile. The intensity profile may be formed by dividing the mass axis into sub-intervals, calculating quantile values for each sub-interval, and transforming the quantile values by computing the logarithms and calculating the differences between successive values. A reference profile may be calculated by determining the arithmetic mean of the individual intensity profiles. An individual spectrum may then be normalised to the reference profile by transforming the reference profile back into quantile values, considering the quantile values of the individual spectrum and of the reference profile as reference points of a transfer function, and applying the transfer function to intensity values of the individual spectrum.