Higher plants n-alkane profiles as indicators of anthropogenic environmental

Abstract

ABSTRACT The saturated biomarkers compositions of thirty angiosperms were analyzed by gas chromatography-mass spectrometry. The concentrations of the sum of 28 target n- alkanes (designated as∑28 n- alkanes) in the plants ranged from 1403 to 115405, 951 to 79441, 659 to 149855, 968 to 172191 and 2883 to 53284 ng/g in Uzere, Oginni, Olomoro, Irri and Calabar plants, respectively. M. sapientum showed high concentrations and strong bioaccumulation potential for n-alkanes among the studied plants. There is a marked distribution pattern among the n-alkanes in the plant; C27-C34 accounted for over 70% in most of the plants studied maximizing at C31 and C33. The mean Carbon preference index, pristane/phytane, pristane/C17, phytane/C18, odd-even predominance and natural n-alkane ratios ranged from 4.7 to 24.3, 0 to 2.8, 0.3+0.4, 0.6+0.9, 0.2 to 4.9 and -3.5 to 1.0 respectively. Applying these conventional n-alkane source diagnostic ratios, the n-alkane in the plants has strong fossil fuel combustion and petroleum inputs which further affirm the petrogenic pollution of soils, sediments and water bodies in the studied locations. The high concentrations of low molecular homologue members (C9 to C18) which hitherto has not been reported by previous workers in higher plants shows that they will serve as good markers to further establish anthropogenic contamination of an area. Key words: n-alkanes, pollution, diagnostics indices, petroleum, higher plants