(1) Department of Chemical Engineering, Clarkson University, Potsdam, NY, 13699-5708, U.S.A.;(2) Department of Chemistry and Biochemistry, Brigham Young University, Provo, UT, 86402, U.S.A.
Abstract:
The diurnal variations in the concentrations of reactive oxygen species (ROS) in various size fractions were determined for
ambient particles in Rubidoux, CA. Sampling of particles was conducted at 3 h intervals using a cascade impactor. The collected
particles were reacted with dichlorofluorescin (DCFH), a non-fluorescent probe that fluoresces when oxidized. The factors
affecting the diurnal variation in ROS concentration were also investigated with special emphasis on the relation between
ROS concentration and the intensity of photochemical reactions where the ozone concentration was taken as an index. The intensity
of photochemical reactions was found to be a moderate factor affecting the daytime ROS concentration. The concentration of
ROS was found to be higher on the smaller particles of the ambient aerosol.
An erratum to this article is available .