%0 Journal Article
%T DISTRIBUTIONS AND SOURCES OF ALIPHATIC HYDROCARBONS AND KETONES IN SURFACE SEDIMENTS FROM THE CROSS RIVER ESTUARY, S.E. NIGER DELTA, NIGERIA
%A OROK E. OYO-ITA
%A BASSEY O. EKPO
%A DANIEL R. OROS
%A BERND R.T. SIMONEIT
%J Journal of Applied Sciences in Environmental Sanitation
%D 2010
%I 
%X Surface sediments from the Cross River estuary were analyzed for the quantitative determination of aliphatic lipids such as n-alkanes, n-alkanones and unresolved complex mixtures (UCMs) of branched and cyclic hydrocarbons. The concentrations of the hydrocarbons, including pristane and phytane, were in the range of 0.02-16.84 mg kg-1 (mean 2.23 ¡À 2.25 mg kg-1 dry weight). The high standard deviations for the n-alkanes most likely reflect the variation in sediment grain size and differences in quantity and quality of organic matter source input. Carbon preference indices for the full range of n-alkanes varied from 0.81 and 4.0, indicating both biogenic and residual petroleum origins. Some samples exhibit odd-to-even carbon number predominances, indicating an input from terrestrial plant waxes and/or macrophytes, whereas even-to-odd carbon number predominances were observed for other samples and are linked to industrial and/or microbial origins. Different distributions and elution ranges of UCMs were also observed, suggesting varied levels of petroleum contamination. Utilization of the LHC/SHC (long/short) ratio, ranging from 0.21-7.49, assisted in the evaluation of dominant trends for terrestrial plant and/or macrophyte-derived versus phytoplankton-derived organic matter inputs; while the parameter, Paq, allowed discrimination of the origin of long-chain n-alkanes and the importance of macrophyte contributions to the river system. Series of n-alkan-2-ones ranging from C15 to C35, with concentrations between 0.10 and 5.62 mg kg-1 (mean 0.82 ¡À 0.44 mg kg-1 dry weight) were identified and are considered to have a common origin from direct incorporation of epicuticular plant waxes on the basis of the regularity in their CPI values (1.19-1.21, odd-to-even). Phytone is thought to be a photo-induced microbial oxidation product from incorporated phytol and/or of direct input from tropical higher plant waxes.
%K Distribution
%K sources
%K alkanes
%K alkan-2-ones
%K UCM
%K Cross River estuary
%U http://www.trisanita.org/jases/asespaper2010/ases01v5n1y2010.pdf