Rate constants for the gas-phase reactions of ozone and nitrate radicals with the sesquiterpenes: valencene and farnesol.
Int J Chem Kinet 2013 Aug; 45(8):508-514
Sesquiterpenes are constituents of a variety of essential oils that are used in flavorings, perfumes, personal care, and cleaning products. Two sesquiterpenes that are commonly used as indoor fragrances are valencene and farnesol. Knowing the reaction rate constants of these chemicals with ozone (O3) and nitrate radical (NO3&bull) is an important factor in determining their fate indoors. In this study, the bimolecular rate constants of kO3+valencene (0.35+/-0.9) × 10 -16, kO3+farnesol (21+/-5.2) × 10 -16, kNO3&bull+valencene (7.9+/-2.0) × 10 -12, and kNO3&bull+farnesol (44+/-11) × 10-12 cm3 molecule-1 s-1 were measured using the relative rate technique at 297 +/- 3 K and 1 atm total pressure. Using the rate constants reported here and measured/modeled indoor concentrations of O3 and NO3&bull (20 ppb and 1 ppt, respectively), pseudo-first-order-rate lifetimes k'O3+valencene (0.06), k'O3+farnesol (3.8), k'NO3+valencene (0.7), and k'NO3·+farnesol (3.9)h-1 were determined.
Oils; Food-additives; Cleaning-compounds; Indoor-environmental-quality; Aerosol-dispensers; Aerosols; Molecular-structure; Models; Odorizers; Chemical-composition; Chemical-properties; Chemical-reactions
Jason Ham, Exposure Assessment Branch, Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Morgantown, WV 26505
Healthcare and Social Assistance; Services
International Journal of Chemical Kinetics