A comparison of deconvolution methods as applied to high performance liquid chromatography–diode array detector–electrospray mass spectrometry of 2- and 3-hydroxypyridine at varying pH in the presence of severely tailing peak shapes

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

“…In Fig 4a it is apparent that peaks 5 and 6 dominate in the analysis and lie in totally different directions-these correspond to the most intense peaks in the chromatogram both with different spectral characteristics. An expansion of the plot shows that peaks 2 and 7 lie in the same The characteristics of the compounds expected in this type of chromatogram have been described in detail in a previous paper, 5 from where it was suggested that peaks 6 and 7 correspond to chlorophyll a, I, and its epimer, IA, whereas peak 2 corresponds to 13 2 -hydroxy-chlorophyll a, II. Since all three compounds exhibit identical spectra, they all lie in the same direction in a PC plot.…”

“…Peak 8 corresponds to pheophytin a, V, in which the central Mg atom is replaced by two hydrogens. Peak 4 is likely to be chlorin e 6 -13 1 -15 2 -dimethyl-17 3 -phytyl ester, IV, and having been found to display a different spectrum to all other chlorophyll a allomers, 5 lies in a From the plot of PC2 versus PC1 for the loadings (Fig. 4b), some information on the wavelengths characteristic of these compounds can be deduced.…”

“…In recent papers, 4,5 we propose that more information can be obtained by simultaneously monitoring a chromatogram using both mass spectrometry and electronic absorption spectroscopy as applied to a simple example of 2-and 3-hydroxypyridines. In this paper, we extend the methods to a more complex real world case study.…”

Quantitative resolution of overlapping tailing peaks obtained by diode-array detector high performance liquid chromatography in the absence of pure standards using simple chemical knowledge

“…The importance of the work in this paper is that straightforward physical knowledge about spectra and chromatographic profiles reduce the solution space. In previous papers 17,18 we included knowledge about relative concentrations, but in this work we do not assume this information.…”

“…16 In recent papers, methods for tailing peak shapes have been reported where only the fastest eluting compound has a composition 1 region. 14,17 It has been shown that this condition together with other knowledge and constraints on the system is sufficient to provide good deconvolution. 18 This is compatible with theoretical predictions by Manne in 1995.…”