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 (overla pping). Two data matrices, one from each detector, were obtained. The peaks hape characteristics of each type of data differed because of the different flow mechanisms between elution from the column and detection. A mass spec trometric data matrix with comparable characteristics to the diode array da ta was obtained by interpolation, baseline correction, mass selection, alig nment using correlograms, low pass filtering to remove background noise, an d peak fitting. Normalised derivatives, procrustes analysis and an integrat ed form of deconvolution based on multiple linear regression were applied t o both data matrices. The use of asymmetric (Gaussian-Lorentzian) peakshape s for modelling the mass spectrometric data was shown to be an important st ep. A consensus chromatogram and spectra are produced summarising data from both detectors.