A method for processing a set of spectra, particularly NMR spectra, by selecting a principle spectral range, recording a plurality of principle spectra in the principal spectral range, obtaining a reference principal spectrum in the principal spectral range, carrying out, for each one of the principal spectra, a bin-wise division of the principal spectrum by the reference principal spectrum to obtain a corresponding set of spectral quotients; calculating, for at least one of the principal spectra, an associated set of statistical measures derived from the corresponding set of spectral quotients, and carrying out, for at least one of the sets of statistical measures, an outlier detection test.