Affiliation: Laboratory of Electrochemical Sensors, Chemistry Department, Federal University of Parana, 19081, Curitiba, Brazil.
The present work proposes a simple, accurate and low-cost method employing simultaneous detection (conductometric and potentiometric) during a precipitation titration using silver nitrate as titrant for diltiazem hydrochloride (DTZ) determination. Both methods were based on the chemical reaction between chloride ions coming from diltiazem hydrochloride molecule and Ag(I) ions, yielding the precipitate AgCl(s). The conductance of the solution and the electric potential of the cell (using an Ag-wire electrode) were measured as a function of the volume of titrant. Under optimized experimental conditions the method was applied for DTZ determination in pharmaceuticals and the results obtained are in close agreement with those obtained using an official method proposed by the British Pharmacopoeia.