| Photochemical aerosol formation from toluene, m-xylene and 1,3,5-trimethylbenzene was investigated in the York University Smog Chamber, in the presence of excess nitric oxide.; Between 0.1 and 1ppm of hydrocarbon was oxidized with HO radicals, in seeded and unseeded experiments, and the aerosol yield was determined from gas- and particle-phase measurements.; The hydrocarbon concentration was monitored with a gas chromatograph (HP 5890) equipped with an FID and the mass concentration of particles was determined by integrating size distributions measured with a differential mobility analyzer (TSI 3071) and a condensation nucleus counter (TSI 3010), assuming a density of 1 g cm−3 for the condensed organic material. For seeded experiments, the volume of the inorganic particles was subtracted from the total before calculating the final mass.; The aerosol yield is defined as the ratio between the organic particulate mass concentration formed and the reacted parent hydrocarbon mass concentration. (Abstract shortened by UMI.)... |
