Functional Group Analysis of Interferometric Data from Gas Chromatography Fourier Transform Infrared Spectroscopy

Abstract

A method is presented for the direct analysis of interferometric data from gas chromatography Fourier transform infrared spectroscopy (GC/FTIR). A synthetic interferogram is initially produced which represents the characteristic absorption features of a particular functional group or compound class. A zero displacement correlation is performed between this test interferogram and each sample interferogram from the GC data. The presence of the desired functionality in the GC effluent is indicated by a small value of the resulting cumulative sum. A “correlogram” which emulates the response from a chemically specific GC detector is obtained by plotting the cumulative sum from each sample correlation. Synthetic interferograms representing infrared absorption bands which are truly specific for a particular functionality yield the best results.