title: On the copper(II)-EDTA-par system for visual and photometric end-point detection in iron(III)-EDTA titrations.
abstract: The copper(II)-EDTA-PAR system is proposed as indicator for direct EDTA titration of 0.2-20 mg of iron(III) in acetic acid medium. The precision and accuracy have been evaluated by spectrophotometric titration. Microtitrations determine down to 10 mug of iron. A logarithmic concentration diagram has been constructed to present the complex equilibria involved. In an interference study the masking agent ammonium fluoride was found to improve the end-point detection. The method has been applied successfully to practical standard samples and compares favourably with other EDTA titrations of iron.
authors.affiliation: Department of Analytical Chemistry, University of Sofia, 1 Anton Ivanov Avenue, Sofia 26, Bulgaria.
authors.forename: D
authors.initials: D
authors.lastname: Nonova
authors.forename: N
authors.initials: N
authors.lastname: Lihareva