Integrated processing of triply coupled diode array liquid chromatography electrospray mass spectrometric signals by chemometric methods

Diode array liquid chromatography electrospray mass spectrometry of 2- and 3-hydroxypyridine was recorded at pH 4.8 (well resolved) and pH 5.0 (overlapping). Two data matrices, one from each detector, were obtained. The peakshape characteristics of each type of data differed because of the different flow mechanisms between elution from the column and detection. A mass spectrometric data matrix with comparable characteristics to the diode array data was obtained by interpolation, baseline correction, mass selection, alignment using correlograms, low pass filtering to remove background noise, and peak fitting. Normalised derivatives, procrustes analysis and an integrated form of deconvolution based on multiple linear regression were applied to both data matrices. The use of asymmetric (Gaussian–Lorentzian) peakshapes for modelling the mass spectrometric data was shown to be an important step. A consensus chromatogram and spectra are produced summarising data from both detectors.