OXIDATION OF DICYCLOPENTADIENE IN SURFACE-WATER

Electron impact (EI) and chemical ionization gas chromatography/mass s pectrometry were used to identify four oxygenated derivatives and char acterize a fifth derivative of dicyclopentadiene in methylene chloride extracts of wastewater and ground water from the Rocky Mountain Arsen al near Denver, Colorado. Based on their EI fragmentation patterns and resistance to trimethylsilylation, putative structures of these deriv atives were proposed, and authentic standards were synthesized. For st ructural confirmation, aliquots of each water extract were spiked with a synthetic standard, and coelution of each of four environmental dic yclopentadiene derivatives with one of the standards was demonstrated on three different capillary gas chromatography columns. In addition, the EI mass spectra of each of the four environmental derivatives and the corresponding synthetic standards were found to be essentially ide ntical. Two monoepoxides, one ketone and a monoepoxide-ketone derivati ve of dicyclopentadiene were identified in wastewater from a sewage tr eatment facility that had been contaminated by ground water. An extrac t of activated charcoal that had been used to remove dicyclopentadiene wastes from contaminated ground water was found to contain the same k etone derivative, dicyclopentadien-1-one, but no epoxide derivatives. Next, it was demonstrated in vitro that the three monooxygenated dicyc lopentadiene derivatives could be formed by light-catalyzed autoxidati on independently of microbial metabolism.