Spectrophotometric determination of copper in pharmaceutical and biological samples with 3-[2-[2-(2-hydroxyimino-1-methyl-propylideneamino)-(ethylamino]-ethyl-imino]-butan-2-one oxime).

3-[2-[2-(2-hydroxyimino-1-methyl-propylideneamino)-ethylamino]-ethyl-imino]-butan-2-one oxime, (H(2)mdo) reacts with copper(II) to form a highly stable 1:1 complex in alkaline medium at room temperature. The complex gives a maximum absorption at 570 nm with a molar absorptivity coefficient of 0.16 x 10(4) l mol(-1) cm(-1). A spectrophotometric method using this ligand was developed and optimized in terms of pH, stability of the complex, amount of reagent required, sensitivity, linearity and tolerance limits of various foreign ions. The linear range for copper determination is 0.2-225 mg l(-1). The method is sensitive, accurate and tolerant to many foreign substances, and, all the reagents used are stable under the conditions. Moreover, the method is easy to perform for the determination of copper in pharmaceutical and biological samples.