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Volume 46, Number 1
(January - February 2001) |
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Volume 46, Number 1
(January - February 2001) |
Membrane Based on Decyl-18-crown-6 for Potassium Selective Sensor
by Elena Hopartean1, Elena Maria Pica2, Coroian Ana1, Viorica Cosma1, Ioana Hopartean1
1Institute
of Chemistry, Fantanele 30, 3400 Cluj-Napoca, Romania
2Technical
University of Cluj-Napoca, Muncii 105, 3400 Cluj-Napoca, Romania
Key words: crown ethers, potassium PVC membrane sensor, potassium potentiometric, determination, ion-selective electrode, ionophores
Four kinds of 18-crown-6 derivatives were studied as ionophores in plasticized
poly(vinyl chloride) (PCV) in order to obtain potassium selective membrane.
The properties of the sensor were studied in detail. For the optimization
of the selectivity toward K+ over Na+
the influence of the following factors was studied: nature and concentration
of the ionophore; nature and concentration of the plasticizer and lipophilic
salt addition. The potassium ion-selective membrane electrode was designed.
The electrode has a fast and Nernstian response in the 1 x 10-1-
2 x 10-5 mol l-1
K+, after six months of continuous measurements.
The change of pH in the range 2-10.5 does not affect the response of the
electrode. The internal resistance of the electrode was measured. The electrode
shows a good stability and can be used in the potentiometric determination.
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