ION-SELECTIVE ELECTRODE MEMBRANE FOR CADMIUM IONS DETERMINATION

摘要

FIELD: chemistry.;SUBSTANCE: invention relates to the field of ionometry, in particular to the development of ion-selective electrodes with membranes based on polymer supramolecular systems. Proposed invention is intended for direct potentiometric determination of activity of cadmium cations in aqueous solutions and can be used in ecological monitoring of waste water, in process and biological solutions. Disclosed is a membrane of an ion-selective electrode for determining cadmium ions, which contains a polymer matrix, a plasticiser, a lipophilic additive and an active component in which the polymer matrix used is polyvinyl chloride, and the plasticizer used is dibutyl phthalate. Electrodogent component used is a phosphoryl-containing pond-2,6-bis[2-(diphenylphosphinyl)phenoxy]pyridine, and the lipophilic additive is sodium tetrakis(4-fluorophenyl)borate dihydrate with the following ratios of membrane components, wt%: electroactive active ingredient 1–3 lipophilic additive 0.5–1.5, plasticiser 65-71PVX 27–32.;EFFECT: invention improves limit of detection of cadmium ions to 2,1⋅10^-6M in aqueous solutions, as well as increase the selectivity of determining cadmium in the presence of copper, zinc, lead, as well as many alkali and alkali-earth metals.;1 cl, 1 ex, 3 tbl