Eric S. C. Kwok, Sara M. Aschmann, Roger Atkinson and Janet Arey
The products of the gas-phase reactions of the OH radical
with o-, m- and p-xylene, in the
presence and absence of NOx, have been
investigated using direct air sampling, atmospheric-pressure
ionisation tandem mass spectrometry (API–MS).
Partially and fully deuteriated xylenes were also studied.
In addition to ion peaks due to tolualdehydes and
dimethylphenols, ion peaks observed from the xylene,
[2H6]xylene and
[2H10]xylene reactions are attributed
to the [M+H]+ ions of the
C4-unsaturated dicarbonyl HC(O)CHCHCHO,
C5-unsaturated dicarbonyls such as
CH3C(O)CH
CHCHO and its isomers,
C6-unsaturated dicarbonyls such as
CH3C(O)CH
CHC(O)CH3 and its
isomers, C8-di-unsaturated dicarbonyls such as
CH3C(O)C(CH3)
CHCH
CHCHO
and its isomers, C8-unsaturated epoxy-dicarbonyls
and, possibly, C8-epoxy-cyclohexenones, and their
partially and fully deuteriated analogues. Possible reaction
mechanisms leading to the observed products are presented.