Review of UCR (University of California-Riverside) protocol for determination of OH (hydroxyl radicals) rate constants with VOC (volatile organic chemicals) and its applicability to predict photochemical ozone production

Technical Report · Sun Nov 01 04:00:00 EST 1987

OSTI ID:5675184

Bufalini, J J; Arnts, R R

The experimental protocol for determining the rate constants for reactions of hydroxyl radicals (OH) with volatile organic chemicals (VOCs) as developed by the University of California-Riverside group is evaluated. Limits of detection and precision are discussed. The protocol is to be used as a measure of the ozone-forming potential of a VOC; a compound with a high OH rate constant also very often produces high levels of ozone. Adaptations of the protocol for compounds containing halogen atoms are suggested. The protocol may not be applicable for compounds that do not produce RO/sub 2/ and HO/sub 2/ radicals such as carbon disulfide. Also, compounds that are free-radical scavengers such as phenol, benzaldehyde, and amines may not give high levels of ozone even though they may have a high rate of reaction with OH radicals. The long chained paraffins also present problems with the protocol since the RO/sub 2/ radicals produced after reacting with OH radicals in air do not oxidize NO to NO/sub 2/ but instead combine with the NO to form nitrates. When this occurs, it is recommended that the protocol be complemented with smog-chamber experiments in order to establish the reactivities of VOCs.

• Research Organization: Environmental Protection Agency, Research Triangle Park, NC (USA). Atmospheric Sciences Research Lab.
• OSTI ID: 5675184
• Report Number(s): PB-88-130059/XAB; EPA-600/3-87/046
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400500 -- Photochemistry
500200* -- Environment
Atmospheric-- Chemicals Monitoring & Transport-- (-1989)
54 ENVIRONMENTAL SCIENCES
ATMOSPHERIC CHEMISTRY
CHEMICAL REACTIONS
CHEMISTRY
HYDROXYL RADICALS
MATTER
ORGANIC COMPOUNDS
OZONE
PHOTOCHEMICAL REACTIONS
PRODUCTION
RADICALS
VOLATILE MATTER