Aliphatic and aromatic hydrocarbons in tropical recent sediments of Campos dos Goytacazes, RJ, Brazil

作者：Gomes AD; Azevedo DD^*

来源：Journal of the Brazilian Chemical Society, 2003, 14(3): 358-368.

• hydrocarbons
• sediments
• PAH
• isoprenoid
• (C/N) ratios
• organic matter

Sediment samples from the Imbe, the Urubu and the Ururai rivers and from Lake de Cima were studied. These sites are located in the county of Campos dos Goytacazes, Rio de Janeiro, Brazil. Aliphatic and aromatic fractions were analyzed by GC-FID and GC-MS in order to gather information on the degree of contamination by anthropogenic activities and other biogenic contributions. Concentrations of total aliphatic and aromatic hydrocarbons were 1.2, 2.8, 5.8 and 4.3 mug g(-1) and 74, 30, 722 and 340 ng g(-1) in the Imbe, Ururai, Urubu rivers and Lake de Cima, respectively. The C(20) highly branched isoprenoid alkane was identified in the Urubu sediment. There were no hopanes or steranes in any sample. Anthropogenic aromatic compounds, detected at trace levels, were observed only in the Imbe and in Lake de Cima (227 ng g(-1)). The fluoranthene/pyrene rate for Lake de Cima was 4.2, suggesting a combustion origin for the PAH. This data is consistent with the frequently sugar cane burning practice that occurs in this region. A greater input from higher plants was observed in the Urubu, Imbe and Lake de Cima sediments; on the other hand, the aquatic input predominates for Ururai. In summary, Lake de Cima sediment is considered very slightly polluted, while the others are unpolluted.

• 出版日期2003-6