What is the national standard of copper powder?

What is the national standard of copper powder?

         The commonly used method for determining high-content copper is still the old method of iodometric method. The amount of potassium iodide is large, costly and time-consuming, and the newly developed photometric method is not suitable for the determination of high content copper due to the problem of copper color developer. Therefore, it is necessary to research and develop new color developers. The author tried to control the pH value with acetic acid-sodium acetate buffer solution, and used ethylenediaminetetraacetic acid disodium salt (EDTA) as a color developer to determine the high content of copper in copper powder, while using EDTA to mask elements such as zinc and aluminum. Eliminate its interference. Cu^2+ and EDTA form a blue complex with a molar ratio of 1:1. The maximum absorption wavelength of the complex is 2=730nm, the molar absorptivity is ε=88.9, and the copper ion content is in the range of 12-24mg/50mL. There is a good linear relationship inside, the linear regression equation is A=0.0354+0.02317c, and the linear correlation coefficient is R=0.9995. The high content of copper in copper gold powder was determined by EDTA spectrophotometry. The results were satisfactory and had development and application prospects. It is especially suitable for small and medium-sized enterprise laboratories with relatively simple equipment.