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GAS-PHASE OXIDATION PRODUCTS OF BIPHENYL AND POLYCHLORINATED BIPHENYLS (R825377)
Citation:
Hites, R. A. AND W. W. Brubaker. GAS-PHASE OXIDATION PRODUCTS OF BIPHENYL AND POLYCHLORINATED BIPHENYLS (R825377). ENVIRONMENTAL SCIENCE & TECHNOLOGY. American Chemical Society, Washington, DC, 32:3913-3918, (1998).
Description:
Our laboratory recently measured the gas-phase reaction rate constants of
polychlorinated biphenyls (PCBs) with the hydroxyl radical (OH) and concluded
that OH reactions are the primary removal pathway of PCBs from the atmosphere.
With the reaction system previously employed for kinetics, we have now
investigated the products of these PCB-OH reactions. Experiments were carried
out in either air or He as the diluent gas at approximately 1 atm in a 160-mL
quartz chamber. Temperatures ranged between 318 and 363 K in order to enhance
the vapor pressures of these less volatile compounds. OH was produced in situ by
the photolysis of ozone in the presence of H2O. Reaction products
from biphenyl, the three monochlorobiphenyls, and five dichlorobiphenyls were
extracted from the chamber, derivatized by diazomethane, and analyzed by gas
chromatographic mass spectrometry (GC/MS). Experiments gave benzoic acid and the
appropriate chlorinated benzoic acids in significant product yields (8-17%).