A Study of a Method of Determination of Nickel in Presence of Iodine and its Determination in Presence of Cobalt

Department of Chemistry, Faculty of Science, University of Tripoli, Libya Manuscript received 18 April 1973; revised 3 January 1975; accepted 5 April 1975 This paper describes an investigation of the appropriate method for the nickel determination. The complexes of nickel-oximes (dimethylglyoxime, 1,2 cycle. hexandiondioxime (nioxime) and α-furildioxime) extracted to a small extent by chloroform from acidic medium (\(p\)H 1-3), have not any peak in visible region, which means that the determination of nickel by this method is not practicable. In the presence of iodine the complexes of nickel-oxime in acidic medium shows absorption peaks, But adding sodium thiosulphate, in order to get rid of excess of the iodine, and shaking the organic solution for a short time would cause these peaks to disappear. The complex of nickel dimethylgyoxime and the complex of nickel-nioxime in alkaline medium were extracted by chloroform and exhibitd a considerable absorption in visible region, but no peak in the visible region was observed when iodhne was added. The complex of nickel- α-furildioxime with and without iodine exhibits a remarkable absorption in the visible region (440-460 nm). This peak does not disappear when the excess of iodine is destroyed by sodium thiosulphate