2012 Volume 61 Issue 4 Pages 166-170
In absorption refrigeration systems, it is necessary to maintain adequate concentration of inhibitor, especially that of molybdate, in an absorbent, i.e. concentrated LiBr solution, to keep the constructive materials free from corrosion damage. In order to propose an alternative to the current management method based on chemical analysis, electrochemical approach has been introduced for in situ analysis of molybdate in an absorbent in this study. Molybdate ions are successfully reduced on a glassy carbon electrode to give cathodic current which clearly depends on the concentration of molybdate. Because the cathodic polarization causes deposition of molybdenum (IV) oxide, successive anodic polarization is effective to quantify the amount of the deposits. Based on the redox phenomena of molybdenum species on a glassy carbon electrode as demonstrated in this study, the electrochemical technique can be applied to the practical management of adsorbent.