Spectrophotometric extractive titrations-III Simultaneous determination of silver and copper in high purity lead.

A procedure for the simultaneous determination of silver and copper in high-purity lead is given. After dissolution of the sample the majority of the lead is removed by precipitation with ammonium sulphate. Silver and copper are then determined by spectrophotometric extractive titration at pH 4.3-5.5 with dithizone. Changes of absorbance are measured at 550 mmu. The procedure has been checked by the method of standard additions and by comparison with conventional methods. The procedure is highly selective. The limit of determination is 2.5 x 10(-5)% of silver and 1.1 x 10(-5)% of copper.