MECHANISTIC STUDIES OF THE ATMOSPHERIC OXIDATION OF METHYL BUTENOL BYOH RADICALS, OZONE AND NO3 RADICALS

In a recent field study, strong indications have been obtained that 2- methyl-3-buten-2-ol (methyl butenol, MBO) is a compound emitted in imp ortant quantities by some types of vegetation. The atmospheric oxidati on products from MBO are not yet well known. In this investigation we studied the reaction mechanisms and products of the reaction of MBO wi th OH radicals, O-3 and NO3 radicals. All the experiments were perform ed in a 480 l Teflon coated Pyrex glass chamber equipped with a long p ath length FTIR spectrometer. As products from the reaction between MB O and OH we identified and quantified acetone, glycolaldehyde, formald ehyde, formic acid, CO and CO2. From the reaction between MBO and O-3, the products acetone, formaldehyde, formic acid, CO and CO2 have been identified; also, 2-hydroxy-2-methyl-propanal (HMPR) is tentatively p ut forward as a product on the basis of HPLC and CC-MS analysis of the DNPH derivative. Organic nitrates, peroxynitrates and carbonyl nitrat es, together with acetone were observed as products of the reaction be tween MBO and the nitrate radical. Tentative reaction mechanisms for t he oxidation of MBO by OH radicals, O-3 and NO3 radicals are proposed. (C) 1998 Elsevier Science Ltd. All rights reserved.