FLOTATION-SPECTROPHOTOMETRIC METHOD FOR THE DETERMINATION OF MERCURY USING IODIDE AND BRILLIANT GREEN

This paper describes a sensitive spectrophotometric method for the det ermination of mercury, based on the flotation of a mercury iodide-bril liant green complex with cyclohexane at pH 5 and dissolution of the co mplex in acetone. The absorbance of the complex is measured at 625 nm. Beer's law is obeyed from 4-500 mu g/l of mercury. The method is high ly sensitive (epsilon = 5.96 x 10(5) l mol(-1) cm(-1)) and selective, as it is free from interferences by almost all cations and anions in t he presence of EDTA. Furthermore, a two-level orthogonal array design as a chemometric method has been used for optimization of the various parameters involved. The method has been successfully applied to paper industry effluents.