Atomic absorption spectrometry and polarographic determination of the copper(I)/copper(II) ratio in borate glass

Abstract

The direct current polarographic behaviour of Cu^II and Cu^I in the presence of 0.15 mol l^–1 triethanolamine, 0.2 mol l^–1 potassium thiocyanate and 30%(v/v) acetonitrile consists of two reduction waves. The first wave for the reduction of Cu^II to Cu^I was found to be reversible, whereas the second wave corresponding to the reduction of Cu^I to Cu^O was found to be irreversible. The stability of both oxidation states of copper in acetonitrile and triethanolamine as a solvent has been studied. The effect of different cations and anions as well as the pH were investigated. The first wave for Cu^II was used for analytical determination of Cu^II in a mixture of Cu^II and Cu^I, while Cu^I was calculated from the difference between the total copper concentration determined by AAS and Cu^II determined by polarography.