Na, K Kim, YP Moon, KC 2024-01-21T09:32:41Z 2024-01-21T09:32:41Z 2021-09-01 2003-02 1352-2310 https://pubs.kist.re.kr/handle/201004/138892 Concentrations of volatile organic compounds (VOCs) were measured at a site in central Seoul from 8 to 13 September 1998. On each sampling day, three 2-h-integrated canister samples were collected in the morning, afternoon and evening, respectively, to observe diural variations of VOCs. Most of the VOCs species showed diurnal variations with higher concentrations during the morning and evening, and lower concentrations during the afternoon. However, in the afternoon, the concentrations of aromatic compounds, closely correlated with solvent usage such as toluene, ethylbenzene, m-lp-xylene, and o-xylene, were slightly higher than or comparable to those in the morning. This may be due to the increase of evaporative emissions derived from the rise in ambient temperature and additional sources such as the use of solvents in painting, printing and dry cleaning. To estimate the participation of individual VOCs in ozone formation, propylene equivalent concentrations were calculated. The results showed that toluene was the most dominant contributor to ozone formation as well as ambient VOC concentrations. Toluene/benzene and m-/p-xylene/ benzene ratios showed a high observed in the afternoon and a low observed in the morning and evening. This may be because the contribution of evaporative emissions by solvent usage on the ambient VOC concentrations is more dominant than those of vehicle-related emissions and photochemical loss. (C) 2002 Elsevier Science Ltd. All rights reserved. English PERGAMON-ELSEVIER SCIENCE LTD NONMETHANE HYDROCARBONS AIR-QUALITY OZONE APPORTIONMENT EMISSIONS NMHC Diurnal characteristics of volatile organic compounds in the Seoul atmosphere Article 10.1016/S1352-2310(02)00956-1 1 ATMOSPHERIC ENVIRONMENT, v.37, no.6, pp.733 - 742 ATMOSPHERIC ENVIRONMENT 37 6 733 742 scie scopus 000181152500001 2-s2.0-0037289715 Environmental Sciences Meteorology & Atmospheric Sciences Environmental Sciences & Ecology Meteorology & Atmospheric Sciences Article NONMETHANE HYDROCARBONS AIR-QUALITY OZONE APPORTIONMENT EMISSIONS NMHC VOCs diurnal variations propylene equivalent concentration evaporative emission solvent usage