Chandravanshi B.S. (PhD)Refera Tesfaye2018-06-262023-11-092018-06-262023-11-091998-06http://etd.aau.edu.et/handle/12345678/3463A new preconcentration and voltammetric method was developed for the determination of Co(TI) with N-p-chlorophenylcinnamohydroxamic acid (CPCHA) modified carbon paste electrode. The measurements were carried out using cyclic voltammetry and differential pulse anodic stripping voltammetry with closed circuit deposition of cobalt(II) at the electrode surface. The effects of several experimental parameters such as modifier composition in the carbon paste electrode, pH and concentration of supporting electrolyte, deposition potential, deposition time, and other instrumental parameters were studied for analytical application. A linear response ""as obtained in the concentration range 1 x 10-6 - 4 x 10.5 M Co(II) with a detection limit of 3,3 x 10.7 M for a 5 min deposition time. A relative standard deviation of 3 . 1 % was obtained for eight successive determinations of 1 x 10.5 M Co(JI). Many coexisting metal ions had little or no effect on the determination of cobalt(II). The method was applied for the determination of cobalt in vitamin B!2' The new electrode offered many attractive properties such as high stability, self cleaning ability, the use of non-dearated solutions and can be used repeatedly without regenerationenCobaJt(II) at N-p-ChIOI'ophenylcinnamohydt'oxamic AcidThesis