Instrumental Dependence of Optimal Interferogram Sampling for Gram-Schmidt Reconstructions of Gas Chromatography/Fourier Transform Infrared Data

Three different commercial FT-IR spectrometers were used to collect GC/FT-IR data for assessing the effects of interferometer stability on the optimal parameters to use for Gram-Schmidt chromatographic reconstructions. Disagreements in the literature regarding the optimum region of the interferogram to use for vector reconstructions are shown to result from interferometer stability differences. It is determined that the use of double-sided vectors in the Gram-Schmidt calculation simplifies the choice of reconstruction parameters. Additionally, it is demonstrated that the Gram-Schmidt algorithm outperforms integrated spectral absorbance methods for any logical choice of Gram-Schmidt parameters.