Spectrophotometric determination of cobalt with zephiramine

Abstract

Zephiramine reacts with thiocyanatocobalt (II) complex ion to form bright blue precipitate. The precipitate is extracted with chloroform, and the extract is extremely stable and has an absorption maximum at 625 mμ. The mole ratio of cobalt and zephiramine in the extracted complex is 1: 2. The formation of precipitate and the efficiency of chloroform extraction are not influenced by the pH in the acidic region. Beer's law is obeyed over the range of cobalt concentration 1.2 ppm to 12 ppm. Many metal ions in their amounts comparable to that of cobalt do not interfere, but 0.1 ppm Fe and 0.8 ppm Cu do interfere. © 1965, The Japanese Society of Physical Fitness and Sports Medicine. All rights reserved.