"An extension of the inverse GLC'technique to the study of the oxidation of asphalts is reported. In the new approach, an asphalt, serving as the liquid substrate in a gas liquid chromatographic column, is oxidized directly within the chromatograph. The retention behavior of a group of selected test compounds possessing different functional groups is determined before and after oxidation. Because the retention behavior is dependent on interactions between the functional groups of the test compound and chemical functionalities in the asphalt, the changes occurring in tile asphalt on oxidation are reflected as changes in retention behavior. Inverse GLC was found sensitive in detecting changes that take place on oxidation, and holds promise as a method of predicting asphalt durability."