Separation of Cobalt(II) from nickel(II) by using dithizone extraction and rate-controlling effect of 1,10-phenanthroline

Hiroshi KAWAMOTO, Hideo AKAIWA
1987 Analytical Sciences  
Although Oh and Freiser' suggested the possibility of the separation of cobalt(II) from nickel(II) based on a difference in the extraction rate of these ions with dithizone (3-mercapto-l,5-diphenylformazan=H2dz), their idea has not yet proved successful in practice.2 Recently the present authors have shown that the degree of mutual separation of the above metal ions with dithizone can be improved remarkably by introducing 2,2'-dipyridyl (dpy) as an additive3, where Ni(dpy)32+ is considered to
more » ... is considered to be inert toward Hdz. Thus preliminary formation of Ni(dpy)32+ before shaking should prevent nickel(II) from being extracted. In the present work, quantitative separation of cobalt(II) from nickel(II) with dithizone is achieved by controlling the extraction rate of nickel(II) using 1,10phenanthroline (phen) instead of dpy.
doi:10.2116/analsci.3.573 fatcat:tax4lr5gxbexrh3eeaxsadii4q