ELECTROD FLUOR-SELECTIV

Mariana DÎRU, Ecaterina VÎLCU Universitatea de stat din Moldova

Abstract

FLUORIDE-SELECTIVE ELECTRODE 

A specific anionic sensor has been prepared, based on trinuclearchromium(III) pivalate as sensing material incorpo-rated into the plasticized PVC-membrane. The sensor exhibited Nernstian response (55,78 mV/decade) in the region between 10-1-10-4 mol/L with a detection limit of 2,0∙10-5 mol/L for fluoride. The working pH of the electrode was in the 5-6 range. The sensor has a response time 30-60 s and can be used for least 3 month. The potentiometric selectivity coefficients were determined by separate solution method. Application of these electrodes to the analysis of toothpaste containing fluoride has been realized and experimental results have been compared with the data on the prospectus. 

Keywords: potentiometry, fluoride-selective electrode, trinuclearchromium(III) pivalate.