G. Malmquist et R. Danielsson, ALIGNMENT OF CHROMATOGRAPHIC PROFILES FOR PRINCIPAL COMPONENT ANALYSIS - A PREREQUISITE FOR FINGERPRINTING METHODS, Journal of chromatography, 687(1), 1994, pp. 71-88
In fingerprinting methods, small differences between chromatograms wit
h rather complex appearance have to be detected. Pattern recognition m
ethods based on principal component analysis (PCA) could be a useful t
ool, but for chromatographic profiles as input data a severe problem i
s the great impact of chromatographic variations compared with true va
riations in sample composition. The problem has been analysed in terms
of parameter variations for exponentially modified Gaussian peaks, an
d a procedure has been developed to align a sample chromatogram toward
s a target chromatogram in order to compensate for (i) small shifts in
retention time (not due to different sample components), (ii) common
variations in peak area (not due to sample composition) and (iii) vari
ations in level and slope of the baseline. The effects of the alignmen
t procedure on the PCA is demonstrated for a set of chromatographic pr
ofiles intended for peptide mapping.