title: Diffusion layer titration of dipyrone in pharmaceuticals at a dual-band electrochemical cell.
abstract: This paper describes the use of a thin-layered dual-band electrochemical cell operating at flow conditions to determine dipyrone (sodium salt of 1-phenil-2,3-dimethyl-4-methylaminomethanesulfonate-5-pyrazolone) by reaction with electrogenerated iodine. The electrolytic cell consisted of two closely spaced gold electrodes, the upper stream electrode serving as the generator electrode and the downstream electrode working as the collector electrode. A linear dynamic range from 2 to 15 mumol l(-1) dipyrone was obtained by using a sample volume of 100 mul, with a detection limit of 1.1 mumol l(-1). Standard deviation (S.D.) of 3.4% for 20 repetitive injections of a 40 mumol l(-1) dipyrone solution and sampling frequency of 90 h(-1) were achieved. The results obtained with the thin-layered dual-band electrochemical cell for dipyrone determination in three different pharmaceutical samples compared well with those found by iodimetry with coulometrically generated iodine.
authors.affiliation: Instituto de Química, Universidade de São Paulo, Av. Prof. Lineu Prestes, 748, 05508900 São Paulo, SP, Brazil.
authors.forename: Thiago R L C
authors.initials: TR
authors.lastname: Paixão
authors.forename: Renato
authors.initials: R
authors.lastname: Camargo Matos
authors.forename: Mauro
authors.initials: M
authors.lastname: Bertotti