Abstract：The experimental conditions for the determination of copper and zinc in brass by EDTA complexometric titration were studied. A simple method for the continuous determination of copper and zinc in brass was established. The sodium thiosulfate was used for the coordination masking of copper ions. The zinc ions in solution were titrated with EDTA standard solution at pH 5.5 using 1-(2-pyridineazo)-2-naphthol (PAN) as indicator. The content of zinc was calculated based on the consumed volume of EDTA standard solution. Meanwhile, the copper and zinc ions in solution were titrated with EDTA standard solution using 1-(2-pyridineazo)-2-naphthol (PAN) as indicator. The content of copper could be calculated based on volume difference of consumed EDTA standard solution for the titration of copper and zinc and the titration of zinc. The proposed method was applied to the determination of copper and zinc in certified reference materials of brass, and the found results were consistent with the certified values. The precision test of sample was also conducted. The relative standard deviations (RSD, n=10) of copper and zinc were both less than 0.55%.
