METHOD FOR DETERMINING CONCENTRATIONS OF FLUORIDE IONS IN ELECTROLYTES Russian patent published in 2024 - IPC G01N27/27 G01N27/333 

FIELD: physical and chemical analysis.

SUBSTANCE: method is disclosed for determining the concentrations of fluoride ions in electrolytes by the direct potentiometric method using a lanthanum fluoride ion-selective electrode and a reference electrode, including the construction of a calibration dependence using standard solutions; the pH value of the analysed sample is controlled using a pH-selective glass electrode. In this case, the construction of a calibration dependence for a lanthanum fluoride ion-selective electrode is carried out using standard solutions with concentrations of 10^-6-10^-2 mol/l sodium fluoride and at the same time a direct potentiometric measurement of tetrafluoroborate ions is carried out using a tetrafluoroborate-selective electrode with a membrane made of polyvinyl chloride, quaternary ammonium base and dibutyl phthalate, and a reference electrode, including the construction of a calibration curve using standard solutions with concentrations of 10^-6-10^-2 mol/l of sodium tetrafluoroborate, all electrodes are immersed in the analysed solution of an organic salt of tetrafluoroboric acid with a concentration of 0.1 mol/l, and measurements are carried out over 3 hours.

EFFECT: determination of the concentrations of fluoride and tetrafluoroborate ions in their joint presence.

1 cl, 3 ex