THE STUDY OF 2-METHYL-8-HYDROXYQUINOLINES AS IONOPHORES FOR CATION-SELECTIVE ELECTRODES
Mariana DÎRU, Universitatea de Stat din Moldova, Natalia TACHI, IPLT Liviu Deleanu, Chișinău
Abstract
In this paper, a comparative study of cation-selective electrodes with the same polymer film composition was performed. The following components were used to prepare the membrane: polyvinyl chloride, a matrix in which all the
components are embedded; tetrahydrofuran, a solvent for all components; ionophore 2-methyl-8-hydroxyquinoline;
plasticizer 2-nitrophenyloctyl ether.3 sensors were assembled from the prepared membranes, and the sensors were
preconditioned in Cu2+, Pb2+, Hg2+ solutions. The electrode preconditioned in solutions containing Hg2+ ions have an
anionic function. The electrode preconditioned in solutions containing Pb2+ ions has a cationic function with a slope
of 25 mV/decade of activity, a detection limit of 2.5·10-5 mol/L, and a concentration range, in which the Nernst function is respected 10-1-10-4M. The electrode preconditioned in solutions containing Cu2+ ions have a cationic function,
with a slope of 25.9 mV/decade of concentration, a detection limit of 1.58·10-5 mol/L and a range of concentrations
in which the Nernst function is respected 10-1 -10-4 mol/L.
Keywords: cation-selective electrodes, 2-methyl-8-hydroxyquinoline, potentiometry.
