Determination of Extractable and Bound Organochlorine in Sediment by Instrumental Neutron Activation Analysis

Extractable organochlorine (EOC) and bound organochlorine (BOC) compositions in sediments from Lake Bosomtwi have been determined with instrumental neutron activation technique. Within the limit of experimental errors, the precision and accuracy of the method for the determination were within 3% and 4% respectively. The mean levels of EOC and BOC were in the range of 1.71 mg/kg to 5.18 mg/kg and 0.31 mg/kg to 0.68 mg/kg respectively. Analysis of organochlorine data showed the EOC content on the average was about seven times more than those of BOC. Washing of chloride from sediment fortified with an insoluble chloride, thus PbCl2, with various concentrations of sodium nitrate (NaNO3) solutions was investigated and washing with 0.1 M solution of NaNO3 gave the optimum yield of chloride. Organic carbon (OC) and BOC compositions in the sediments were subjected to correlation analysis and results showed that the two correlated very well with corrected coefficient of 0.65. OC in sediments could therefore, be one of the carrier phases of BOC in sediments.