| Full text | |
| Author(s): |
Alvim, Debora Souza
;
Gatti, Luciana Vanni
;
Correa, Sergio Machado
;
Chiquetto, Julio Barboza
;
Rossatti, Carlos de Souza
;
Pretto, Angelica
;
dos Santos, Maria Helena
;
Yamazaki, Amelia
;
Orlando, Joao Paulo
;
Santos, Guaciara Macedo
Total Authors: 10
|
| Document type: | Journal article |
| Source: | AIR QUALITY ATMOSPHERE AND HEALTH; v. 10, n. 4, p. 421-435, MAY 2017. |
| Web of Science Citations: | 13 |
| Abstract | |
High-ozone concentrations currently represent the main air pollution problem in the city of So Paulo, Brazil. To elucidate the main volatile organic compounds (VOCs), which act as ozone precursors, samples from air quality monitoring stations were evaluated. Thirty-five samples were collected in August-September of 2006 and 43 in July-August of 2008, when the consumption of ethanol was about 50 % of the total fuel used in the S (a) over tildeo Paulo Metropolitan Area. Samples were collected using electropolished stainless canisters. Chemical analyses were performed on pre-concentrated samples followed by gas chromatograph with flame ionization and mass spectrometry detection. The incremental reactivity scale was used to rank the ozone precursors using the Ozone Isopleth Package for Research (OZIPR) trajectory model coupled with chemical mechanism Statewide Air Pollution Research Center (SAPRC). Sixty-nine species of VOCs were quantified, and the ten main ozone precursors identified in 2008 were as follows: formaldehyde (42.8 %), acetaldehyde (13.9 %), ethene (12.2 %), propene (5.1 %), 1-methylcyclopentene (3.0 %), p-xylene (2.4 %), 1-butene (2.1 %), trans-2-pentene (1.9 %), 2-methyl 2-butene (1.7 %) and trans-2-butene (1.6 %). Volatile organic compound mass distribution showed that in 2008 alkanes represented 46 % of the total VOCs, alkenes 27 %, aromatics 14 %, alkadienes 1 % and aldehydes 12 %. (AU) | |