Spectrophotometric estimation of cobalt(II) with nitrilotriacetic acid

A convenient and efficient method for the estimation of cobalt(II) ions in the presence of other metal ions is described. Interference of metal ions such as iron(II), iron(III), nickel(II), manganese(II), and copper(II) have been investigated. Only iron(III) ions seriously affect this determination. Copper(II) and nickel(II) ions do not interfere if present in a molar-ratio less than 1:2 in the cobalt(II) ion solution. Cobalt(II)-nickel(II) and cobalt(II)-copper(II) binary mixtures can be efficiently analyzed at selective wavelengths.