Hydrogen and Carbon Monoxide at Terra Nova Bay (ANTARCTICA)

Abstract

Studies on atrazine ozonation performed in methanol containing solutions showed a strong influence of the methanol content which might favour direct O₃ reactions as compared to processes induced by OH radicals. The importance of the slackening effect on the degradation rate of atrazine (which demonstrates a scavenger activity) was evaluated in various solvent compositions and pseudo-kinetic constants k' were found to be in the 10^?3-10^?2 s^?1 range. The appearence rate of deethylatrazine as major oxidation product was thus also modified (k' values between 10^?4 and 10^?3 s^?1). Several by-products were detected which are either related to deethylatrazine (intermediates or oxidation products) or belong to competitive pathways. Among them, a number of formamides (a new class of atrazine ozonation products) were identified using MS and MS-MS techniques. These compounds are produced by oxidation of the N-ethylamino group likely through a non radicalar process. Deschloro-triazines were also characterized as structures whose formation specifically depends on the presence of methanol.