Lipid biomarkers profile—presence of coprostanol: recent sediments from Rodrigo de Freitas Lagoon—Rio de Janeiro, Brazil

Abstract

Coprostanol (contribution characteristic from anthropogenic pollution) and other lipid biomarkers (sterols, fatty alcohols and fatty acids) were identified and quantified in recent sediment extracts from Rodrigo de Freitas Lagoon, a touristy spot of Rio de Janeiro—Brazil, using gas chromatography with mass selective detector (GC-MSD). The determination of lipid biomarkers profile indicates an autochthonous biogenic contribution due to the presence of phytoplankton, zooplankton, bacteria and dinoflagellates. The allochthonous biogenic contribution was confirmed by detection of biomarkers from higher plants in the sediments due to the influence of the Atlantic Forest inserted in the studied region. The concentration of the studied compounds varied from 5.53 to 216.47 μ g.g^{− 1} for sterols, 0.47 to 5.35 μ g.g^{− 1} for fatty alcohols, 20.15 to 66.22 μ g.g^{− 1} for fatty acids and 0.08 to 3.98 μ g.g^{− 1} for coprostanol. The presence of coprostanol was attributed to illegal untreated sewage discharge in the pluvial collector which ends up in the Lagoon.

Keywords:

• Biomarkers
• sediments
• lagoon
• sterols
• fatty acids
• fatty alcohols
• coprostanol

Acknowledgments

This work was supported by CAPES and CNPq. FEMMA (Fundação Estadual de Engenharia e Meio Ambiente—Rio de Janeiro) is acknowledged for bibliographical support on Rodrigo de Freitas Lagoon.

Notes

^a except phytol and farnesol;

^b lipid extracts submitted to saponification;

^c non saponified lipidic extracts;

^d the acid extract of sediment from sampling point 7 was not obtained;

^e linear saturated fatty alcohols; SFAs: saturated linear fatty acids; brFAs: branched fatty acids; MUFAs: monounsaturated fatty acids; PUFAs: polyunsaturated fatty acids.