title: Arsenazo III as metallochromic indicator for complexometric determination of calcium in slightly alkaline medium.
abstract: Arsenazo III is proposed as metallochromic indicator for calcium in slightly alkaline medium. The visual titration with EDTA was performed at pH 8 and 40 microg-12 mg of calcium were determined. The interference of some ions was considered and it was found that phosphate does not interfere appreciably. Spectrophotometric detection of the end-point was used for titration of calcium in the presence of magnesium at pH 9. For the estimation of the titration error, the conditional stability constants of the calcium-arsenazo III complex were found.
authors.affiliation: Department of Chemistry, University of Sofia, Sofia 26, Bulgaria.
authors.forename: V
authors.initials: V
authors.lastname: Michaylova
authors.forename: N
authors.initials: N
authors.lastname: Kouleva