Assessing anthropogenic contamination in surface sediments of Niger Delta, Nigeria with fecal sterols and n-alkanes as indicators.

The occurrence of sterols and n-alkanes in surface sediments from rivers and canals in the Niger Delta, Nigeria, determined with a gas chromatography-mass spectrometry method, was used to assess the impacts of anthropogenic activities in the area. The concentrations of total sterols (∑₈Sterol) and n-alkanes (∑₂₈n-alkane) in the sediments ranged from 133 to 2040 ng/g and 474 to 79,200 ng/g, respectively. An evaluation of the source diagnostic indices indicated that petroleum related sources (petrogenic) were the main contributor of n-alkanes in the samples, with minor contribution from higher plants waxes (biogenic), while the sterols were mainly of biogenic origin.

Assessment of organochlorine pesticides residues in higher plants from oil exploration areas of Niger Delta, Nigeria.

The concentrations and distributions of organochlorine pesticides (OCPs) in some higher plant samples collected from oil exploration areas of the Niger Delta, Nigeria were examined. The concentrations of Σ(25)OCP ranged from 82 to 424, 44 to 200 , 34 to 358, 33 to 106 and 16 to 75 ng/g in Olomoro, Oginni, Uzere, Irri and Calabar plants, respectively. The compositional profiles of the analysed OCPs in most of the plants showed no fresh inputs in the area.

Biomonitoring potentials of polycyclic aromatic hydrocarbons (PAHs) by higher plants from an oil exploration site, Nigeria.

Higher plants sampled from a moderately polluted exploration site were analyzed with gas chromatography-mass spectrometry to determine the occurrence and sources of polycyclic aromatic hydrocarbons (PAHs). The concentrations of the sum of 28 target PAHs (designated as Σ(28)PAH) in the leaves of higher plant samples ranged from 365 to 2870 μg/kg with an average of 1430 μg/kg. The majority of the target compounds were detected except 9,10-diphenyl anthracene and dibenzo(a,h)anthracene, which were below the detection limits in most plant samples.

Phytochemical and antimicrobial studies of four species of Cola Schott & Endl. (Sterculiaceae).

The in-vitro antimicrobial evaluation of ethanol extracts of four species of Cola Schott & Endl. was done using human isolated strains of Staphylococcus aureus, Staphylococcus albus, Bacillus subtilis, Klebsiella pneumonia, Pseudomonas aeruginosa, Candida albicans, Aspergillus niger as test organisms. The assays were carried out by agar well diffusion, erythromycin and ketoconazole served as the control drugs.