Commonly used methods to determine the high content of copper is still the old iodine quantity method, the dosage of potassium iodide, high cost, time consuming, and the recent development of photometric method of copper chromogenic agent problems should not be in the determination of high content of copper, therefore it is necessary to research and develop new chromogenic agent. The authors try to acetic acid and sodium acetate buffer solution pH control, using ethylenediamine tetraacetic acid disodium salt (EDTA) as chromogenic agent, determination of high content of copper in copper powders, at the same time using EDTA masking the elements such as zinc, aluminium to eliminate the interference. Cu ^ 2 + and EDTA generate blue mole ratio of 1:1 complex, the maximum absorption wavelength of the complex of 2 = 730 nm, the molar absorption coefficient for the epsilon = 88.9, copper ion content within 12-24 mg/ml 50 had good linear relationship, the linear regression equation for A = 0.0354 + 0.02317 c, the linear correlation coefficient R = 0.9995. Using EDTA spectrophotometric method for determination of high content of copper in copper powders, the result is satisfactory, there are development and application prospect, especially applicable to the equipment is simple laboratory medium and small enterprises.
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