Electroanalytical determination of copper and lead in nitric acid solution containing small amounts of hydrochloric acid

In the analysis of copper-base alloys, chiefly brasses fI.nd bronze, difficulties have been encountered in consistently obtaining quantitative depositions of copper in nitric acid solutions, unless the nitric acid solution of copper is either fumed with sulfuric acid or evaporated to dryness and baked moderately. As a result of experiments made to remedy this trouble, it has been found that complet e deposition of copper is obtained if a trace of chloride ion (1 drop of 0.1 N hydrochloric acid) is added to the nitric acid solution either during the solution of the alloy or at the beginning of the electrolysis.