The determination of nickel with dimethylglyoxime in the presence of iron and cobalt

A method for the determination of nickel in the presence of both ferric iron and cobalt is presented. The nickel is precipitated directly with dimethylglyoxime, without the prior reduction of the iron. The interference of the iron and cobalt is eliminated by the addition of N,N-dihydroxyethylglycine, which chelates the iron and prevents the formation of the iron-cobalt-dimethylglyoxime contaminant.