COMPOSITION OF ION-SELECTIVE ELECTRODE MEMBRANE FOR DETERMINATION OF CALCIUM IONS Russian patent published in 2020 - IPC G01N27/333 C02F1/00 

FIELD: chemistry.

SUBSTANCE: invention relates to composition of ion-selective electrode membrane for determination of calcium ions, including polyvinyl chloride as polymer matrix in amount of 27–32 wt%, plasticiser in amount of 65–71 wt%, lipophilic additive in amount of 0.5–1.5 wt% and ionophore in amount of 1–3 wt%. Membrane is characterized by that plasticizer used is dibutyl phthalate, as a lipophilic additive – dihydrate tetrakis(4-fluorophenyl)borate of sodium, as ionophore – 1-(methoxydiphenylphosphoryl)-2-diphenylphosphoryl-4-ethylbenzene.

EFFECT: invention improves the detection limit of calcium ions in aqueous solutions, as well as increases the selectivity of determining calcium in the presence of cations of alkali and alkali-earth elements, including biogenic elements, as well as cations of d-elements, which makes it possible to use such electrodes for analysis of biological objects (whole blood, blood serum, urine, et cetera), also when determining content of calcium ions in natural waters.

1 cl, 1 dwg, 3 tbl