A Controlled-Potential and Derivative DC Polarograph for Regular and First and Second Derivative DC Polarography: Circuits, Theory, and Performance Characteristics. Advantages of Rapid and Derivative DC Polarography^†

Abstract

SUMMARY The circuits, theory, and performance characteristics are described of a controlled-potential dc polarograph (ORNL Model Q-1988-FES) which is designed to take advantage of the inherent high sensitivity and resolution of derivative dc polarography. Several circuit modifications for specific applications are described. Cell and electrode design considerations are given. The advantages of potentiostatic electrolysis in polarography, the advantages of the use of current-averaging and analog derivative circuits in improving the measurement and the interpretation of recorded dc polarograms, the attainment of ultimate high resolution through the recording of first derivative dc polarograms of good waveform, the achievement of high sensitivity by means of rapid derivative dc polarography, the practical advantages of first derivative over regular dc polarography, the relative advantages of first and second derivative dc polarography, and the practical advantages of rapid dc polarography are discussed. Conclusions are illustrated and substantiated by data.