OH radical formation from the gas-phase reactions of O3 with a series of terpenes

The yields of OH radicals from the gas-phase reactions of O3 with a series of C10 terpenes have been measured at 296±2 K and atmospheric pressure of air, using 2-butanol to scavenge the OH radicals formed and measuring the amount of 2-butanone produced. The measured molar OH radical yields are: 2-carene, 0.81±0.11; 3-carene, 0.86±0.11; limonene, 0.67±0.10; myrcene, 0.63±0.09; ocimene (cis-/trans- mixture), 0.55±0.09; α-terpinene, 0.38±0.05; γ-terpinene, 0.81±0.11; terpinolene, 0.74±0.10; and linalool, 0.66±0.10. These OH radical yields are independent of water vapor concentration over the range (0.34–2.7)×1017 molecule cm−3 (5–40% relative humidity). Together with previous measurements in this laboratory of the OH radical yields from the reactions of O3 with α-pinene and sabinene, a consistent data set of OH radical formation yields from the reactions of O3 with monoterpenes are available for atmospheric conditions.