Rapid functional group characterization of gas chromatography/Fourier transform infrared spectra by a principal components analysis based expert system

A procedure for the on-line characterization of compounds eluting from a gas chromatograph (GC) by automated interpretation of their vapor-phase infrared (IR) spectra is described. Principal components analysis (PCA) is applied to a training set containing two classes of appropriately scaled vapor-phase infrared library spectra. A sigmold discriminant function is applied to the results of the PCA. The presence of a given functionality in an unknown spectrum is determined by projection of the unknown spectrum onto the factors defined by the PCA and assigning the projected unknown a discrimination score