Assessment of peak origin and purity in one-dimensional chromatography by experimental design and heuristic evolving latent projections

Abstract A new procedure for assessing peak origin and purity in chromatographic calibration is presented. Chemical analytes were mixed according to an experimental design in order to achieve independent concentration patterns. One-dimensional chromatograms were analysed as digital profiles with the heuristic evolving latent projections (HELP) method after minimization of the retention time shifts between target peaks by a simplex technique. The origin of peaks was assessed by calculating the correlation between concentration patterns, obtained as the first loadings in HELP from principal component analysis (PCA) on selective chromatographic regions, and the patterns in the designed mixtures. Co-eluting impurities and overlapping peaks could be detected, resolved and quantified. Only a few non-overlapping data points were needed to assess the origin of peaks. Latent-variable correlation chromatograms are introduced as a powerful tool for the assignment of chromatographic areas with similar concentration patterns.