Evaluation of platinum electrodes and three electrode potential standards to determine electrode quality Academic Article uri icon

abstract

  • The preinstallation evaluation of Pt electrodes in electrode potential (EH) standards is crucial for reliable field interpretations. During a routine check of electrode quality in three different EH standards before field installation, inconsistent and variable results were recorded. Due to the preliminary observational results, the objectives of this study were to: (i) elucidate why EH readings in the same buffer were different before and after soaking in water, (ii) identify the most rigorous standard for detecting poor electrode function, and (iii) determine causation for disparity in the electrode performance in EH standards when using constructed EH electrodes. Electrodes were evaluated in quinhydrone in pH 4 and pH 7 buffers and ferrousferric sulfate solutions. Additionally, an experiment was developed to intentionally expose Cu in EH electrodes with decreasing area of the metal exposed. Finally, aqueous macroscopic electrochemical and Fourier Transform Infrared spectroscopic evaluations of Cu in the three standards were conducted to characterize and quantify the reductionoxidation reactions of Cu. This study found that quinhydrone in pH 7 buffer was not a rigorous standard for determining improper function of Pt electrodes constructed utilizing Cu wire. Due to the interrelationship between the reductionoxidation potential of Cu and pH, standards with low pH proved to be a more rigorous standard.

published proceedings

  • SOIL SCIENCE SOCIETY OF AMERICA JOURNAL

author list (cited authors)

  • Owens, P. R., Wilding, L. P., Lee, L. M., & Herbert, B. E.

citation count

  • 13

complete list of authors

  • Owens, PR||Wilding, LP||Lee, LM||Herbert, BE

publication date

  • September 2005

publisher