METHOD OF PRODUCTION OF EXPERIMENTAL DATA FOR DETERMINING HYDROGEN CARBONATE-IONS BY METHODS OF CONDUCTOMETRIC AND ACID-BASE TITRATION Russian patent published in 2015 - IPC G01N31/16 G01N27/26 

FIELD: chemistry.

SUBSTANCE: method comprises titration of a sample of mineral water with acid titrant and the resistance measurement in the solution of conductivity cell at addition of each portion of titrant, up to 20 measurements in total, characterised in that the titrant in determining hydrogen carbonate-ions in the mineral water is used as a solution of hydrochloric acid (HCl), to do this 10 ml of mineral water is added to an electrochemical cell with two platinum electrodes with a distance strictly fixed between them, then one drop of 0.1% methyl orange indicator is added into the electrochemical cell, the burette for titration is filled with a solution of hydrochloric acid (HCl), a magnet is placed into the electrochemical cell, and a magnetic stirrer is activated for stirring the solution in the cell, the electrodes via the electrical wires-clips are connected to the desktop portable digital LCR-meter ELC-131D device and it is activated, in titration the experimental data are obtained by two methods simultaneously - the method of acid-base titration, based on neutralising of hydrogen carbonate-ions with hydrochloric acid in the presence of methyl orange indicator, and the conductometric titration after, the addition of each portion of titrant the resistance value (R) of the solution analysed is fixed according to the device, which corresponds to the conductometric titration, and after the solution colour change in the presence of the indicator, namely, the transition of pink colour of the solution into yellow the total volume of titrant (V_TE) is measured according to the burette (the method of acid-base titration), then similarly as described above 3 other samples of water are analysed, having the volume of 10 ml each, and in determining the content of hydrogen carbonate-ions in potable mineral waters the exact concentration of HCl titrant on boron (sodium tetraborate - Na₂B₄O₇·10H₂O) is pre-set.

EFFECT: acceleration and simplification of the analysis.

2 cl, 5 ex, 8 tbl, 1 dwg