Potentiometric relaxation analysis using a selective electrode system

摘要

The concentration of a specific substance is determined in the potentiometric relaxation procedure of DE4100727, with single or twin electrodes. Interference from deposits on electrodes or their coatings, is prevented by enclosing a reaction space around them, with a semipermeable membrane, esp. for long term operations. This is filled with an auxiliary solution, pref. a filtrate of the solution under investigation, and as required, a selective biological component, e.g. an enzyme. The diffusion-process or layering, and subsequent relaxation measurement, are kept short, by limiting the duration of the applied potential difference. Recovery time between successive relaxation measurements is made sufficiently long, that the equilibrium between the solution in the reaction space and the solution to be analysed, re-establishes itself.