ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Derivatives of barbituric acid and of their complexes with metal cations. I. 5-Hydroxy-5-(2-hydroxy-4,4-dimethyl-6-oxo-1-cyclohexenyl)barbituric acid, 5-hydroxy-5-(1,3-indandion-2-yl)barbituric acid and their complexes with Fe(III) cations

E. Kuchár

Department of Analytical Chemistry, Faculty of Natural Sciences, Komenský University, Bratislava

Abstract: Determination of dissociation constants by Potentiometrie measurements is described. The spectrophotometric measurements show that by the reaction of 5-hydroxy-5-(2-hydroxy-4,4-dimethyl-6-oxo-1-cyclohexenyl)barbituric acid with Fe(III) a complex is formed. The combination ratio 1 1 was determined by spectrophotometric titrations, by Potentiometrie and Job methods. The equilibrium constant was found by calculation .analysis. The validity of Lambert—Beer law for the reaction of the reagent with Fe(III) has been checked and the optimal conditions for spectrophotometric iron determination were found. Under the given conditions in the glycine buffer solution at pH 3.4 and  λ= 480 nm, iron may be determined spectrophotometrically in concentrations as small as 1 gμ Fe/ml.

Full paper in Portable Document Format: 229a682.pdf (in Slovak)

Chemical Papers 22 (9) 682–689 (1968)