Mass Spectra (IMAGE) Moscow Institute of Physics and Technology Caption Mass spectra of bitumen from the amphora (A), petroleum from Siberia was exposed to ozone (B), and petroleum from Siberia before exposure to ozone (C). Credit MIPT Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.