Development of New Cs+ Ion‐Selective Electrode with Alkyl‐Bridged Calix[4]arene Crown‐6 Compounds for the Determination of Cs+ in Nuclear Waste Streams

Abstract

AbstractA new liquid membrane based Ion Selective Electrodes (ISE) for Cs+ employing three 1,3 cycloalkyloxy bridged calix[4]arene crown 6 ether compounds (L1: cyclooctyloxy, L2: cyclodecyloxy, L3: cyclotetradecyloxy) as ionophores were developed. The best response was observed when L3 was used as an ionophore. The cation exchange resin DOWEX‐50 W was used to maintain low activity of Cs+ in inner filling solution (IFS) to improve the performance. With optimized IFS, Nernstian response (56.3 mV/decade of Cs+) over the concentration range 10−7 to 10−2 M of Cs+ was observed. Studies were also carried out to develop all solid contact Cs+ ISE employing gold‐ polyaniline composites as a transducer. Superior response for Cs+ was observed with IFS based ISE. The developed ISE showed detection limit of 3.7x10−8 M Cs+ with response time less than 20 seconds. Separate solution method was applied to determine selectivity for Cs+ over alkali, alkaline earth and transition metal ions. The response of ISE for Cs+ was fairly constant over the pH range 4–11. The concentration of Cs+ was determined in two simulated high level active waste solutions and spiked tap water samples and results agreed well with atomic absorption spectroscopy (AAS) values and expected values, respectively.