Abstract
A simple and rapid method has been established for spectrophotometric determination of cobalt(II) in water after preconcentration by sorbing the nitroso R (sodium-1-nitroso-2-hydroxynaphthalene-3, 6-disulfonate) complex of cobalt(II) on poly(chlorotrifluoroethylene) resin. The cobalt-nitroso R complex was quantitatively retained on the resin as an ion associate complex with tetrabutylammonium cation in the range of pH 5.5 to 8.5. The retention capacity was
41.6μg (0.71μmol) Co g-1 resin at a maximum flow rate of 30ml min-1. Cobalt retained on the resin column was completely extracted with 5ml of methanol which was submitted to spectrophotometric measurement at 550nm after 1ml of 1.0mol dm-3 nitric acid was added. The proposed method was applied to a river water sample.
