ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

High-sensitive electrochemical indication of the end-point of titration

J. Berčík, J. Dzurov, and Z. Krajcerová

Department of Analytical Chemistry, Slovak Technical University, CS-812 37 Bratislava

Abstract: A new high-sensitive electrochemical method for determining the end point of titration has been developed. By using a new kind of pulse polariza­tion of the indication electrode and an indication method for a chosen potential, a considerable improvement of the analytical signal can be achieved while not only the faradaic component of the indication current but also the nonfaradaic component is utilized. The new method, called "Switching potentiostatic amperometry" (SPA) makes possible to indicate the end point of titration with extremely high sensitivity. The model cou- lometric titrations of As(III) and Cr(VI) in concentrations 10^-6—10^-9 mol dm^-3 are presented as examples. The sensitivity of indication defined as the least substance amount in the titrated volume which produces an unambiguous signal in the course of transition through the end point is equal to 10^-11 mol (in the volume 80 cm³) for the SPA method.

Full paper in Portable Document Format: 414a453.pdf

Chemical Papers 41 (4) 453–464 (1987)