APPLICATION OF EVOLVING FACTOR-ANALYSIS IN THERMOCHROMATOGRAPHY

Thermochromatography (ThGC) is a temperature-resolved, multiple-inject ion, gas chromatography technique useful in the study of pyrolysis. Co nsecutive chromatograms are collected during pyrolysis each at known t emperatures and representing the head-space gas component distribution above the pyrolyzing material. Previous work with the ThGC has been l imited entirely to the production of response surfaces of retention/te mperature/FID response. Reported here are experiments where evolving f actor analysis (EFA) is applied to ThGC data structures. The EFA is us ed to resolve overlapping chromatograms based on their different origi n in pyrolysis temperature. Simply, EFA deconvoluted the components of the pyrolysis process as differing thermal reactions leading to diffe rent product profiles. As a result, one gets sets of different chromat ograms and their corresponding temperature profiles in the evolving he ad-space gases. A specific example of analysis of the pyrolysis of an ethylene-propylene-diene rubber is given.