We have delineated similarities and differences in chemical composition among neat asphalt samples obtained from the Strategic Highway Research Program (SHRP) Materials Reference Library in Austin, TX, and oxidized materials prepared by SHRP contractors using thermal chromatography (TC). This unique method for disassembling complex materials for analysis using precise temperature programming in a controlled and well characterized environment was combined with flamie ionization detection (FID) and with gas chromatographic (GC) separation and mass spectral (MS) detection. Our TC/FID analyses provided thermal profiles of materials under study-quantity of evolved species as a function of temperature--, while our TC/MS studies allowed structures to be assigned to the various components evolved from the asphalt matrix. Distinct differences among neat samples and between neat samples and their oxidized counterparts were easily discerned, both in comparisons of thermal profiles and of compound-specific identifications of components