Luminița Vlădescu,* Renate Lerch-Gurguța, Irinel Badea, and Voichița
Marinescu
Department of Analytical Chemistry, Faculty of Chemistry, University
of Bucharest,
2 14 Regina Elisabeta Bvd. 70346 Bucharest, Romania, luminita_vladescu@yahoo.com
ABSTRACT
The present paper describes a spectrometric study on the acid base characteristics of the reagent obtained by coupling 3-methyl-1-phenylpyrazolin-5-one with diazotized amino-aryl-sulfonic acid. The apparent pKa values were evaluated. The reagent is recommended as metal indicator for the complexometric determination of Ti(IV) in buffered solutions at pH = 5.00, without separation as well as pH indicator for the alkaline titration of mixtures of acids, bases and salts.