Derivatives of Rhodanine as Spectrophotometric Analytical Reagents. Determination of Copper

The reaction between Cu(I) and four non pyridinic derivatives of rhodanine (5-(phenyl)methylene-rhodanine (BARH), 5-(0-hydroxy-phenyl) methylenerhodanine (SARH), 5-(p-methoxy-phenyl) methylene-rhodanine (AARH) and 5-indolyl-(3)-methylene-rhodanine (IARH)) have been considered. the influence of the different experimental parameters on the formation of the complexes was studied, and the optimum conditions for the determination of copper were established. The indol-(3)-al derivative was selected among these because of the greater sensitivity of the metal reaction. The precision of the procedure, expressed in terms of relative standard deviation was 1.1 %. The methods have been applied to the determination of copper in several constrasted samples. Finally, these derivatives of rhodanine were compared with others classical reagents used in the photometric determination of copper.