Polarography and Spectrophotometry of Copper‐Glutamate Complex

A deep blue colored chelate compound resulting from the reaction between copper ion and glutamate was studied polarographically and spectrophotometrically. A single reversible wave corresponding to the reduction of the copper‐glutamate complex to the Cu(I) state was observed in the p H range 4.5 to 6.7. Only one kind of chelate compound, CuG 2 = was detected. The electrode reaction is formulated thus CuG 2 = + H + +e=CuG − + HG − The diffusion current constant is 3.13 for 0.2 M glutamic acid and 0.1 M potassium chloride at p H 6.2. The copper‐glutamate complex (1:2) has an absorption maximum at 615 mμ. and its absorbance was constant at the wide p H range 4.2 to 9.2. Its instability constant was calculated to be 3.5×10 −7 .