2.2 Water Sampling and Analysis
Water samples were collected using 10% (v/v) HNO3 acid washed polyethelene plastic bottle. About 1 gallon of water samples were collected from each station. The samples were added with 5mL nitric acid and were transported to the laboratory for digestion and analysis. About 500mL of the sample were transferred to a beaker added with 3ml nitric acid, pH adjusted to less than 2, heated and evaporated to a volume between 10 to 15mL before precipitation occurs. Samples were then filtered using Whatman #5. The filtrate was placed in a 25mL volumetric flask which was diluted to volume. The solution was then exposed to Flame Atomic Absorption Spectroscopy (FAAS) (Shimadzu) for the determination of Cu, Pb and Zn concentration