title: The voltammetric study of 2-mercapto-5-phenylammino-1,3,4-thiadiazole using carbon paste electrodes.
abstract: A rapid and accurate voltammetric method for the quantitative determination of 2-mercapto-5-phenylammino-1,3,4-thiadiazole (MPATD) with carbon paste electrodes (CPE) has been developed. The study was made by cyclic voltammetry between -0.4 and +0.6 V with 50 mV s(-1) sweep rate in aqueous solution. After successive oxidation/reduction cycles we found a total oxidation of MPATD at +0.45 V. As the compound is oxidated, the reduction current peak increases at +0.13 V, indicating an irreversible process. Following only the oxidation process in the -0.1 to +0.6 V range, we investigated the optimum scan rates at different current densities and pH values (realised with buffers, pH between 1.0 and 10.0) with CPE versus Ag/AgCl reference electrode using linear sweep voltammetry. We found a good linear relation between the current peak height and concentration in a 2.5 x 10(-9)-1.25 x 10(-7) mol ml(-1). This method allows the quantitative detection of the MPATD as it or from dosage forms and biological media.
authors.affiliation: Department of Analytical Chemistry, Faculty of Pharmacy, University of Medicine and Pharmacy Iuliu Haţieganu, Cluj-Napoca, Romania. rsandulescu@usa.net
authors.forename: R
authors.initials: R
authors.lastname: Săndulescu
authors.forename: I
authors.initials: I
authors.lastname: Marian
authors.forename: S
authors.initials: S
authors.lastname: Mirel
authors.forename: R
authors.initials: R
authors.lastname: Oprean
authors.forename: L
authors.initials: L
authors.lastname: Roman
mesh_terms: D002623:Chemistry Techniques, Analytical / Q000379:methods*; D004563:Electrochemistry / Q000379:methods*; D004566:Electrodes; D006863:Hydrogen-Ion Concentration; D015394:Molecular Structure; D010084:Oxidation-Reduction; D013830:Thiadiazoles / Q000032:analysis*
chemical_list: C102557:2-mercapto-5-phenylamino-1,3,4-thiadiazole; D013830:Thiadiazoles