MATHEMATICAL-MODELS FOR THE FOURIER-TRANSFORM INFRARED SPECTROSCOPIC DETERMINATION OF ORTHO-XYLENE, META-XYLENE AND PARA-XYLENE IN XYLOL

The analysis of infrared data of binary and ternary mixtures of o-, m- and p-xylene has been carried out using a series of mathematical models, which permit the quantitative analysis of samples by Fourier transform infrared spectroscopy without the need for absorption cells with a known optical pathlength. The relative errors found in the analysis of binary mixtures are of the order of 1.4%, and those found for ternary mixtures are lower than 3.0% in most instances, for samples containing from 10 to 75% m/m of each component. The proposed method can be applied to the analysis of xylol, a paint solvent that contains the three compounds assayed.