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Chromatography, particularly High Performance Liquid Chromatography (HPLC), is probably the most used standard
instrumental analytical technique, widespread over all analytical labs around the world, very convenient to perform fast
separation and simultaneous quantification of several analytes in several complex samples. Most convenient, reliable and
roust detectors are usually related with UV-vis detection such as Diode Array Detectors (DAD). However, when analyzing
real and complex samples, it is frequent to observe signal distortions related with analytes co-elution, spectral interference
and column lack of selectivity. Is it possible to be aware of these situations and circumvent these problems? In this work we
propose Unsupervised Contribution Analysis (UCA) to address these situations; all chromatographic data should be checked
in order to find out the real number of independent contributions that are consistent with dataset in study. In a recent study,
we suggested how to retrieve independent component contributions in spectroscopic (synchronous fluorescence) analysis of
environmental samples. In this work, Independent Component Analysis (ICA) was used in order to retrieve spectral sources
and respective component contributions. However, in order to preform ICA, it was necessary to previously determine the
number of independent components responsible for data spectra. Using Principal Object Analysis (POA), we showed how
it’s possible to find out system independent contributions in a robust and reliable manner. With this same concept, we have
proved the ability of UCA to determine independent contributions; their specific chromatogram and; respective contributions
using same approach, especially when there are evidences for co-elution profiles in (UV/vis)-HPLC and other non-specific
instrumental methods. Some examples, practical and theoretical considerations will be addressed in order to maximize the
ability of Unsupervised Component Analysis (UCA) to evaluate chromatographic response in complex systems.
Jorge Costa Pereira has completed his BSc, MSc and PhD at University of Coimbra. His main research work is in the field of Chemical Analytical Control and Environment Quality Control specially related with statistics, analytical method validation and chemometrics. He has published 30 papers in well reputed international journals and is member of the editorial board or Portugaliae Electrochimica Acta.