Potentiometric Utility of the New Solid-State Sensor Based on Crowned Ionophore for the Determination of K^+


Abstract: All solid-state contact poly vinyl chloride (PVC) membrane potassium-selective electrode has been developed. The construction of the ion selective electrode membrane was organized using ionophore 4,4'-bis[4''-phenoxy(15-crown-5) methyl]benzyl in PVC cocktail. The potentiometric performance characteristics of the electrode were investigated by a computerized system. The electrode was found highly selective to K^+ ions over a wide variety of other cations. The electrode almost exhibited a Nernstian response (\ge 55 (\pm15) mV/decade of K activity) to K^+ within the concentration range 1.5 x 10^{-1} - 1.0 \times 10^{-5} M. The operational pH range of the electrode was 5--7. The response time of the electrode was fast (<10 s), and the life time was long (at least 2 months). The electrode has been successfully used in real sample analysis. The values obtained by the electrode were in good agreement with the certified values.

Keywords: Ion-selective electrodes, Solid-state contact PVC-membrane, K^+ determination.

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