Near-infrared spectroscopy: the new FT frontier--spectroscopic and chemometric considerations

Several orthogonal calibration sets of aliphatic and aromatic hydrocarbon mixtures have been designed to explore the effects of spectral resolution, spectral information within a spectral range, wavenumber imprecision and scale shifts, dynamic range, and noise on the chemometrically derived quantitative calibrations for hydrocarbon mixtures. The first two of these parameters have been studied on six very similar aromatic compounds in this, the first of a series of studies which also include aliphatic straight chain, branched, unsaturated, and cyclic compounds. The 6000 to 9500 cm-1 near-infrared derived chemometric calibration accuracy, as compared to gravimetric values, ranged from less than 0.04% to 0.2% error for each of the six components in the mixtures.