SPECTROPHOTOMETRIC DETERMINATION OF COPPER IN ALKALI METALS AND HYDROXIDES WITH 4,4'-DIHYDROXY-2,2'-BIQUINOLINE

Thirteen new symmetrically substituted derivatives of 2,2'-biquinoline were evaluated as chromogenic reagents. One of these, the 4,4'-dihydroxy derivative, is capable of complexing copper (l) directly in strongly alkaline solutions. A detailed study of the complex and its application for the determination of copper in sodium and potassium metals of hydroxides are reported. Simplicity is achieved in the determination since neutralization of base and pH adjustment are unnecessary. Sensitivity is favored by extractability of the complex. In common with other cuproine reagents, 4,4'-dihydroxy-2,2'-biquinoline is a specific chromogenic reagent for copper (l). © 1969, American Chemical Society. All rights reserved.