Determination of Heavy Metals (Cadmium and Lead) From Tilapia Fish in Oguta Lake, Oguta Local Government Area, Imo State

The uptake of heavy metals by fish from the environment, primarily occurs through gills, food, skin and in fresh water.Some aquatic organisms can store heavy metals up to certain amount, which might not be harmful nor toxic, but can reach to human via food chain, which pose as danger to human health (Merlini, 1971).An experiment was carried out on a tilapia fish gotten from Oguta lake in Imo State, to determine the presence of lead (pb) and cadmium (cd);The fish was prepared for analysis by removing the gills and liver, which was dried in an oven at about 900 c grinded into powdery form, after which 1 gram of the sample was weighed out and was transferred into a digestion flastk. 10mls of HN03 was added to the sample and was heated to about 950 c with reflux of 10-15mins without boiling, this action was repeated at intervals till all the brown fumes was given off at a gentle heating of the sample at the temperature of 350 c.2mls of distilled water and 3mls of 30% of H202 was added aliquotely at intervals until a clean sample of the fish extract was obtained; which was further diluted with 50mls of distilled water, and was filtered out. The filterate was used for the analysis of cadmium (CD) and lead (pb) which was determined through the method of Atomic Absorption spectrometer (AAS), to obtain 0.15 presence of cadmium (cd) and 0.63 of lead (pb); which is within the normal range of FAO/WHO which is (0.04-0-95) of cadmium and (0.00-5.00) of lead respectively.