Sr. Mcdow et al., AN APPROACH TO STUDYING THE EFFECT OF ORGANIC COMPOSITION ON ATMOSPHERIC AEROSOL PHOTOCHEMISTRY, JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES, 101(D14), 1996, pp. 19593-19600
Physical and chemical characteristics of atmospheric carbonaceous aero
sol particles are reviewed and their likely effects on the particulate
matter as a reaction medium are discussed. An approach to studying th
e effects of organic components of atmospheric particulate matter on a
erosol organic photochemistry based on this discussion is described. A
vailable information suggests that atmospheric aerosols from common co
mbustion sources, such as wood smoke or diesel soot, are almost entire
ly carbonaceous, consisting of a relatively thick, possibly liquid org
anic layer coating an elemental carbon core, This implies that organic
compounds are fairly mobile and consequently that overall organic com
position of an atmospheric aerosol could play an important role in the
photochemical behavior of associated reactive organic substances, In
accordance with this a photochemical turntable reactor was used to inv
estigate the effects of organic aerosol constituents dissolved in an o
rganic solvent, using benz[a]anthracene as a model photochemically rea
ctive compound, Preliminary results showed that 4 out of 10 major orga
nic compound classes found in atmospheric aerosols include compounds w
hich accelerated benz[a]anthracene photodegradation. These were methox
yphenols, polycyclic aromatic ketones and quinones, substituted benzal
dehydes, and substituted furans.