2. Materials and methods
Analytical grade reagent and distilled water would used
throughout the study. All glass ware and plastic container
used were washed with detergent solution followed by 20%
nitric acid and then raised with top water and distilled water.
All chemicals and reagents were of the analytical grade and
were obtained from RIEDEL-DE HAEN, Germany. Lead Nitrate,
Copper Sulfate and Zinc Chloride were used for preparation of
Lead, Copper and Zinc standards respectively. Nitric acid was
used for sample digestion.