Quantitative analysis of the Raman spectra of mixtures of weakly interacting components by factor analysis methods

A system of 17 overlapped Raman spectra in the 250-350 cm(-1) spectral regi on of the weakly interacting component mixture of 1,2-dichloroethane, dichl oromethane and carbon tetrachloride has been subjected to the statistical m ethods of target factor analysis (TFA) and evolving factor analysis (EFA). The results have demonstrated that concentrations of substances with intens e bands are successfully determined; however, there are difficulties in ana lyzing weak bands of one of the components, especially when applying a TFA technique. The results of such an analysis can be improved by minimal chang es in one of the coordinates of a rotation vector. Comparison of these resu lts with a synthetic spectral model suggests that problems with analysis of weak bands are caused by the presence of a strong band that greatly overla ps the weak one.