Chemometric techniques for exploring complex chromatograms: application of diode array detection high performance liquid chromatography electrospray ionisation mass spectrometry to chlorophyll a allomers

Abstract

Triply coupled diode array detection high performance liquid chromatography mass spectroscopy is applied to a complex mixture of at least eight chlorophyll degradation products. Derivatives are employed to determine parts of the chromatogram of composition one. Mass selection is performed on the mass spectroscopic data. Principal components analysis is performed on both the raw and simultaneously normalised/standardised data; three dimensional projections of the data are obtained and compared to conventional two dimensional graphs. Angular plots between diode array loadings characteristic of individual compounds and scores of the diode array data are described. In mass spectra, angular plots between loadings characteristic of individual compounds and the remaining diagnostic masses reveal further mass spectral structure.