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This study was conducted to evaluate the levels and seasonal variations of some organochlorine pesticides (OCPs) in the cultivated land of Oke-Osun farm settlement, Osogbo, Nigeria. A field sampling programme was conducted in the rainy and dry seasons for 4 months each resulting in the analysis of a total of 40 samples. Soil samples collected at 20-m intervals were air-dried to a constant weight, sieved through a mesh of 2.0-mm pore size and selected by coning and quartering method. Solid-liquid extraction was used to extract OCPs from the soil. Qualitative identifications and quantitative evaluation of the OCPs were carried out with the aid of a Perkin Elmer gas chromatograph coupled with electron capture detector. Seasonal mean ranges of OCPs in soil (μg/kg) were 13.09 ± 21.66 β-BHC-42.01 ± 17.50 p, p(')-DDT in rainy season and 30.74 ± 17.38 α-BHC-82.88 ± 32.24 p, p(')-DDT in the dry season. The results obtained from this study revealed that agricultural soil samples of Oke-Osun farm settlement were contaminated with persistent organochlorine pesticides mainly as a result of their applications by farmers. Higher levels of OCPs were obtained for dry season than the rainy season. There were indications from this study that pesticides that have deleterious health effects on humans previously placed under legal restrictions by regulatory agencies were still being used by the farmers of Oke-Osun farm settlement and this gives cause for environmental concern.

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The products of the pyrolytic decomposition of some even chain-length copper (II) carboxylates from decanoate to octadecanoate inclusive have been identified, using a flow system, to be copper, carbon dioxide, a carboxylic acid and an odd chain-mength alkene. These products are similar to those reported for the decomposition of mercury(lI) carboxylates. The unexpectedly low (less than unity) CO2/soa p ratio was attributed to the reduction of the CO 2 to carbon monoxide. The carboxylic acid was characterised by wet chemical tests, determining the melting points of the acid and its amide derivative and matching its IR spectrum with that of the authentic acid. Elemental analysis and wet chemical tests were employed for the identification of the alkene.The products of decomposition and mechanism proposed to account for the degradative route of the systems show that good quality thin solid copper oxide films may only be obtained from the decomposition of copper(II), carboxylates if the carrier gas is non-inert (e.g. oxygen).Most of the previous studies in this laboratory [1][2][3][4][5][6][7][8] and elsewhere [9-11] on metal carboxylates (soaps) have focussed attention mainly on their physical properties in the molten phase. For example, in our laboratory, the electrical conductivity, viscosity and heat of phase changes of lead [1,3,6]

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