SIMPLEX FOCUSING OF RETENTION TIMES AND LATENT VARIABLE PROJECTIONS OF CHROMATOGRAPHIC PROFILES

Pre-processing of chromatograms giving digital profiles which can be directly utilized as input data in projection methods is outlined. The methods include a new procedure for retention time adjustment using a simplex method for the optimization of the cross-correlation between target peaks. A graphically assisted method is used for the reduction of data. The pre-processing methods were tested on real data from four different chromatographic analyses. Latent variable projection methods are introduced as a toolbox for quantitative and qualitative interpretation of chromatographic profiles. Different chromatographic drifts which influence the latent variable models were identified. Pre-processed profiles analyzed with projection methods enable to: (1) quantitatively utilize one-dimensional chromatograms from several samples, (2) extract quantitative information from overlapping peaks, (3) obtain information from complex chromatograms without peak identification, and (4) make visual interpretations of the profiles.