IDENTIFICATION AND DIFFERENTIATION OF HEAVY RESIDUAL OIL AND ASPHALT POLLUTANTS IN SURFACE WATERS BY COMPARATIVE RATIOS OF INFRARED ABSORBANCES

To determine the chemical nature of the heavy petroleum products involved in the 1967 Lake Michigan oil spill, a procedure for the characterization and identification of the oily, tarlike materials was needed. Samples from beach water were analyzed by infrared spectrophotometry. The unknown spectra could not be matched with the known spectra, since autoxidation caused changes in the unknown specimen. By comparative ratios of infrared absorbances, the identity of the critical unknown samples was established. Even though asphalt and heavy residual oil have similar infrared spectra, there is a sharp distinction. Samples from seven petroleum companies were tested, using this new method for rapid characterization. © 1969, American Chemical Society. All rights reserved.