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Trace‐Level Determination of Cs + Using Membrane‐Based Ion‐Selective Electrodes
Author(s) -
Radu Aleksandar,
Peper Shane,
Gonczy Chad,
Runde Wolfgang,
Diamond Dermot
Publication year - 2006
Publication title -
electroanalysis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.574
H-Index - 128
eISSN - 1521-4109
pISSN - 1040-0397
DOI - 10.1002/elan.200603542
Subject(s) - ionophore , plasticizer , selectivity , chemistry , membrane , ion selective electrode , detection limit , aqueous solution , ion exchange , alkali metal , inorganic chemistry , nuclear chemistry , vinyl chloride , electrode , chloride , ion , analytical chemistry (journal) , chromatography , polymer , organic chemistry , biochemistry , copolymer , catalysis
A membrane‐based ion‐selective electrode (ISE) has been developed for the trace‐level determination of Cs + in aqueous samples. A systematic evaluation of several ionophores was performed, examining the effect of membrane plasticizer and ion exchanger on sensor selectivity. Poly(vinyl chloride) (PVC)‐based ion‐selective membranes of conventional composition containing calix[6]arene hexaacetic acid hexaethylester as ionophore (Cs I, 10 mmol/kg), bis(2‐ethylhexyl) sebacate (DOS, 66 wt%) as plasticizer, and undecaiodinated closo ‐dodecacarborane (UIC, 4.1 mmol/kg) as ion exchanger exhibited superior performance with respect to selectivity over alkali and alkaline earth metal cations. The unbiased selectivity coefficients, log K $\rm{ {_{Cs,J}^{pot}}}$ , for the principal interfering ions (J=K + , Na + , Ca 2+ , and Mg 2+ ) were determined to be −2.9, −4.7, −8.5, and −8.7, respectively. DOS‐plasticized PVC electrodes containing Cs I and UIC were optimized for trace‐level measurements, exhibiting a lower detection limit of 7.9×10 −9 M Cs + (log a Cs,LDL =−8.1) in the presence of a 1×10 −5 M Na + background. The utility of the optimized ISEs was demonstrated by determining the concentration of Cs + in both drinking water and natural water samples.