Spectrophotometric Determination of Microgram Quantities of Copper in Biologic Materials

摘要

A procedure for the determination of microgram quantities of copper in biologic material is described. The sample is wet-ashed with a nitric acid-perchloric acid mixture. The copper is extracted from an alkaline solution of the ash with a solution of diphenylcarbazide in benzene. Absorbance of the red complex is read at 540 mμ. The copper in as little as 0.5 ml. of serum can be determined and the method is suitable for routine determinations. The use of microcells makes possible the analysis of 0.1 ml. of serum.