Quaternary Alkylammonium and Alkylphosphonium Pertechnetates: Application toPertechnetate Ion-Selective Electrodes

Abstract

Pertechnetate ion-selective PVC membrane electrodes based on quaternary alkylammonium and phosphonium salts (bromides and pertechnetates) were examined. The most favorable ionophore was tetradecyltrimethylammonium bromide. The response function was linear within the concentration range 10^-2-10^-6 mol/L and the slope was 52 mV/pTcO₄. The detection limit remained at 5·10^-7 mol/L. The selectivity and response time of the electrodes was studied and it was found that the electrodes exhibited high selectivity to TcO₄^--anion against the main inorganic components of radioactive waste solutions and environmental waters (nitrate, sulfate, chloride and others). The electrodes response was stable over a wide pH range.