http://hdl.handle.net/11189/5250 2026-09-29T12:34:40Z http://hdl.handle.net/11189/5556 Title: FTIR Spectroelectrochemical Studies on [Ru3(CO)12] and fac-[Re(Cl)(CO)3(4bzpy)2] (4bzpy = 4-benzoylpyridine) Authors: Fatoki, Olalekan S; Mzimba, P Abstract: Incorporation of wire mesh platinum electrodes into a standard infrared solution cell yielded an inexpensive and easy to maintain optically transparent thin layer electrochemical (OTTLE) cell, well suited for IR analysis of species with half-lives of seconds to minutes. As test bed, two reactions were investigated, which are discussed in the literature: (i) for [Ru3(CO)12] evidence was found for at least partial reversibility in the two-electron reduction process to [Ru3(CO)11]2-, and (ii) for fac-[Re(Cl)(CO)3(4bzpy)2] (4bzpy = 4-benzoylpyridine) additional information concerning the two-step electron reduction of the two benzoylpyridine ligands (again partially reversible) could be obtained 2001-01-01T00:00:00Z http://hdl.handle.net/11189/5555 Title: Assessment of polybrominated diphenyl ethers in sediment of Asunle stream of the Obafemi Awolowo University, Ile-Ife, Nigeria Authors: Olutona, Godwin O; Oyekunle, John AO; Ogunfowokan, Aderemi O; Fatoki, Olalekan S Abstract: Assessment of levels of polybrominated diphenyl ethers (PBDEs) from the sediment of Asunle stream, an adjourning stream of the Obafemi Awolowo University dumpsite, has been carried out. Sediment samples were collected from the stream at six locations for a period of 8 months, composed of 4 months each of wet (May–Aug) and dry (Nov–Feb) seasons. Soxhlet extraction was employed for the isolation of all the target compounds from the sediment samples. Extracts were further subjected to multi-layer column chromatography employing different forms of silica gel. The prepared samples were analyzed using GC-MS. The overall mean concentrations of the total PBDEs ranged from 1.80 to 9.46 ng/g. The results showed that the concentrations of the PBDEs were slightly higher during the wet season than those during the dry season. In all the studied locations, BDE28, BDE47, BDE99, BDE100, BDE153, and BDE154 were detected in all the sediment samples at concentrations that ranged from 0.73 to 10.43 ng/g. Results of this study indicated that BDE153 was the major pollutant of the Asunle stream sediments. 2016-01-01T00:00:00Z http://hdl.handle.net/11189/5224 Title: Occurrence of selected polybrominated diphenyl ethers and 2,2′,4,4′,5,5′ hexabromobiphenyl (bb-153) in sewage sludge and effluent samples of a wastewater-treatment plant in Cape Town, South Africa. Authors: Daso, Adegbenro P; Fatoki, Olalekan S; Odendaal, James P; Olujimi, Olanrewaju Abstract: The reuse of treated effluent from wastewater treatment plants (WWTPs) as alternative water source for sport-field or landscape irrigation, agricultural, and other industrial purposes is growing significantly. Similarly, the application of treated sludge (biosolid) to agricultural soils is now being considered globally as the most economic means of sludge disposal. However, the presence of emerging organic contaminants in these matrices, including polybrominated diphenyl ethers (PBDEs), which are potential endocrine disruptors, portends a high health risk to humans and the environment in general. In this study, effluent and sewage sludge samples collected from a WWTP were analysed for some selected PBDE congeners (BDE congeners 28, 47, 99 100 153 154 183, and 209) as well as BB-153 using a high-capillary gas chromatograph equipped with an electron capture detector. The sum of the eight PBDE congeners ranged from 369 to 4370, 19.2 to 2640, and 90.4 to 15,100 ng/l for raw water, secondary effluent, and final effluent, respectively. A similar result was observed for sewage sludge samples, which ranged between 13.1 and 652 ng/g dry weight (dw). The results obtained for BB-153 were generally lower compared with those found for most PBDE congeners. These ranged from ND to 18.4 ng/l and ND to 9.97 ng/g dw for effluents and sewage sludge, respectively. In both matrices, BDE 47 and 209 congeners were found to contribute significantly to the overall sum of PBDEs. The reuse of the treated effluent, particularly for agricultural purposes, could enhance the possibility of these contaminants entering into the food chain, thus causing undesirable health problems in exposed subjects. 2012-01-01T00:00:00Z http://hdl.handle.net/11189/4919 Title: Polycyclic aromatic hydrocarbons (pahs) in food and environmental samples: an overview Authors: Fatoki, Olalekan S; Ximba, Bhekumusa J; Opeolu, Beatrice O Abstract: Polycyclic aromatic hydrocarbons (PAHs) have been widely reported as a class of ubiquitous chemicals in different matrices. Health implications of these pollutants include carcinogenicity and mutagenicity amongst others. The need for effective measurement techniques of these compounds therefore becomes imperative. This paper reviews sources of PAHs into the environment, exposure routes and effects on humans. Furthermore, an overview of different measurement techniques in environmental and food samples is also presented. Extraction methods that have been applied for PAHs quantification include solidphase extraction (SPE), solid-phase microextraction (SPME), stir bar sorptive extraction (SBSE), liquid-phase microextraction (LPME), liquid-liquid extraction (LLE), accelerated solvent extraction (ASE) and solid-liquid extraction. Most commonly used analytical methods are gas chromatography-mass spectrometry (GC/MS), gas chromatography- flame ionization detection (GC/FID), high performance liquid chromatography-fluorescence detection (HPLC/FD) and high performance liquid chromatography- ultra violet detection (HPLC/UV). Levels reported in different media suggest global need for PAHs monitoring in foods and environmental samples. KEYWORDS: Extraction, analysis, polycyclic aromatic hydrocarbons, food, soil and water. 2012-01-01T00:00:00Z