Evaluation of C1eC13 carbonyl compounds by RRLC-UV in the atmosphere of Niterói City, Brazil Soraya de M. Ochs a, b , Flávio C. Albuquerque c , M. Cecília G. Pontes Massa c , Annibal D. Pereira Netto a, b, * a Programa de Pós-Graduação em Química, Instituto de Química, Universidade Federal Fluminense, Outeiro de São João Batista, s/n 24020-141 Centro, Niterói, RJ, Brazil b Departamento de Química Analítica, Instituto de Química, Universidade Federal Fluminense, Outeiro de São João Batista, s/n 24020-141 Centro, Niterói, RJ, Brazil c Centro de Pesquisas e Desenvolvimento Leopoldo Américo Miguez de Mello, CENPES, PETROBRAS, Av. Horácio de Macedo, 950, Cidade Universitária, 21941-598 Rio de Janeiro, RJ, Brazil article info Article history: Received 13 January 2011 Received in revised form 3 June 2011 Accepted 9 June 2011 Keywords: Carbonyl compounds Carbonyl-DNPH derivatives Air pollution Vehicular emission Rapid resolution liquid chromatography abstract In this present work, the concentration of 31 carbonyl compounds (CC) were determined in the atmo- sphere of Niterói City, RJ, Brazil, between January 9th and 14th, 2010, in 7 periods of two hours in each day. Rapid Resolution Liquid Chromatography with UV detection of the corresponding hydrazones was employed. Formaldehyde, acetaldehyde and acetone were found to be the most abundant CC in all the 42 samples. Experimental data showed one period of maximum concentration of CC that occurred between 10:00 and 12:00 h, regardless of the day, with concentrations varying between 16.20 and 52.30 mgm 3 . The ratios of the concentrations of acetaldehyde and formaldehyde were 1 in all periods and the mean ratio was 2.0. The results obtained were lower than those previously found in Rio de Janeiro City, indicating that Niterói is a less polluted area in terms of this criterion. This is a novel work related to the aspects that concern the determination of most CC in the atmosphere of Niterói City and medium size Brazilian cities. Ó 2011 Elsevier Ltd. All rights reserved. 1. Introduction Carbonyl compounds (CC) have a prominent role in air pollution. They are sources of free radicals as well as precursors of organic aerosol in urban areas (de Andrade et al., 2002) and also contribute to ozone formation in the troposphere (Zurek et al., 2000; Fujioka and Shibamoto, 2006). There are a large number of sources of aldehydes and ketones to the atmosphere. Primary sources include emission by vegetation, industrial plants, cigarette smoke and materials, burning of vegetation and fossil fuels, besides the secondary formation of these substances via photochemical oxidation of hydrocarbons (Wang et al., 2005; Chi et al., 2007; de Carvalho et al., 2008). Several aspects of emission, reactivity and toxicological effects of CC were reviewed (Fujioka and Shibamoto, 2006). The CC are of great importance to atmospheric chemistry due to the strong influence on the formation of nitric acid, perox- yacetyl nitrate (PAN) and other smog components (de Andrade et al., 1998). There is interest in their structural characterization and determination in the atmosphere due to their importance in the smog processes. Moreover, the monitoring of aldehydes and ketones in the atmosphere is of fundamental interest because of their well-known effects on human health. Formaldehyde and acetaldehyde, for example, are considered respectively as carcino- genic and probably carcinogenic compounds by IARC (IARC, 2006; Dutta et al., 2009). The determination of atmospheric CC was conducted in different places of the world (Foster et al., 1996; Muller, 1997; Possanzini et al., 2000; Cecinato et al., 2001; Pereira et al., 2004; Motyka and Mikuska, 2005; Ho et al., 2006; Rubio et al., 2006; Chi et al., 2007; Pal and Kim, 2007; de Carvalho et al., 2008; Pal et al., 2008). Different aspects of experimental conditions for determination of CC in the atmosphere were recently reviewed (Pal and Kim, 2007). There are data of the determination of aldehydes and ketones of low molecular weight (mainly formaldehyde, acetaldehyde and acetone) in different parts of the world, including Brazil. However, there are relatively few studies of the determination of CC of high molecular weight, which may include unsaturated, branched and aromatic compounds (de Carvalho et al., 2008). Comparatively, less is known about their effects upon the atmospheric photochemical processes and also human health. * Corresponding author. Programa de Pós-Graduação em Química, Instituto de Química, Universidade Federal Fluminense, Outeiro de São João Batista, s/n 24020- 141, Centro, Niterói, RJ, Brazil. Tel.: þ55 21 2629 2221; fax: þ55 21 2629 2143. E-mail addresses: sorayaochs@yahoo.com.br (S.deM. Ochs), annibal@vm.uff.br (A.D. Pereira Netto). Contents lists available at ScienceDirect Atmospheric Environment journal homepage: www.elsevier.com/locate/atmosenv 1352-2310/$ e see front matter Ó 2011 Elsevier Ltd. All rights reserved. doi:10.1016/j.atmosenv.2011.06.022 Atmospheric Environment 45 (2011) 5183e5190