Electronic Controlled-Potential Coulometric Titrator

Abstract

Oak Ridge National laboratory, Oak Ridge, Tenn. b A simple electronic instrument for coulometric redox titrations a t controlled potential is described. The potential of only the electrode a t which the desired reaction occurs is controlled by a stabilized difference amplifier combined with a transistor current amplifier. The electrolysis current is integrated by a stabilized amplifier. The integral is read out a s a voltage. Either manual or automatic titrations may b e made. The instrument is alternating current lineoperated. It is very stable and gives titration results of good precision which are obtained by calculation from Faraday's law.LEGANT electronic instruments for E coulometric redox titrations a t controlled potential have been described by Booman (1, 2) and illerritt, Martin, and Bedi (5). Electrolysis at controlled potential provides electrochemical selectivity. The principles and applications of controlled potential coulometric titrations have been reviewed by these authors and by Lingane (4). The instruments described by Booman and by Merritt et al. electronically integrate the electrolysis current by different methods and results of good precision are obtained by both.The electronic controlled-potential coulometric titrator uses the methods of control of electrode potential and of electronic integration described by Booman. It has the advantage of simplicity, which is reflected in lower costs of fabrication and of maintenance. Only the potential of the electrode a t which the desired reaction occurs is controlled.

Anodic Oxidation Pathways of Aromatic Amines. Electrochemical and Electron Paramagnetic Resonance Studies

“…Large-scale controlled potential electrolyses for spectrophotometry were carried out with a controlled-potential coulometer. 10 In this case the cell contents, after electrolysis, were transferred by gravity flow to the optical cell of a Cary Model 14 spectrophotometer. For transient optical spectra, a platinum gauze was placed directly in the optical path, and the controlled potential electrolysis was carried out in situ.…”

Determination of Europium(II) and Total Europium in Europium-Activated Lithium Iodide Scintillation Crystals.

“…Stop the titration and record the read-out voltage. The weight of europium (total) titrated is equal to the product of the read-out voltage and the europium coulometric factor, 6.315 mg. of Eu per volt (4,11).…”

Controlled Potential Coulometric Analysis of Amine-Oxides of Pharmaceutical Interest

“…Although these polarographic studies indicate the feasibility of controlled potential reduction of N-oxides, quantitative studies have not been reported. EXPERIMENTAL Equipment-Controlled potential electrolyses were performed using an electronic controlled potential coulometric titrator, model Q-2005, ORNL (12). A Non-Linear Systems digital voltmeter, model 484 A, displayed the readout voltages.…”