F. Faude et J. Goschnick, XPS, SIMS AND SNMS APPLIED TO A COMBINED ANALYSIS OF AEROSOL-PARTICLES FROM A REGION OF CONSIDERABLE AIR-POLLUTION IN THE UPPER RHINE VALLEY, Fresenius' journal of analytical chemistry, 358(1-2), 1997, pp. 67-72
The water acceptance of aerosol particle surfaces is a key factor for
atmospheric hygiene as it initiates gravitational settling by water up
-take. To examine the concurrent influences on the surface of real air
borne particles concerning the deposition of hydrophobic organic mater
ial, six particle sampling campaigns were performed in polluted outdoo
r-air under different air conditions. The particles were examined with
SNMS, SIMS, and XPS with special view of the chemical inventory of th
e surface region. The total elemental inventory obtained with SNMS sho
ws carbon compounds in all particle size classes. Soot seems to govern
the submicron particles while the coarse fraction contains soil dust
or fly ash. Depth-resolved analysis shows organic carbon compounds to
be surface-enriched and to dominate the composition of the topmost mol
ecular layers of the particles independent of the collection time and
particle sizes. However, chlorides and ammonium sulfate were also foun
d at the surface which will always reduce the hydrophobicity of the su
rface caused by organic compounds. No correlation was discovered betwe
en the ozone or NO2 concentration of the air and the type and quantity
of the organic surface components.