METHOD OF EXPERIMENTAL DATA RECEIPT FOR DETERMINATION OF HYDROCARBONATE IONS IN MINERAL WATERS BY POTENTIOMETRIC AND ACID-BASE TITRATION METHODS Russian patent published in 2017 - IPC G01N33/18 

FIELD: chemistry.

SUBSTANCE: invention can be used to determine hydrocarbonate ions at mineral water analysis by potentiometric titration, which includes titration of the mineral water sample with the acid titrant and pH measurement in the potentiometric cell solution by adding each titrant portion. The solution of hydrochloric acid (HC1) is used as the titrant, the exact concentration of which is set according to the borax (sodium tetraborate- Na₂B₄O₇⋅10H₂O). For that 10 cm³ of mineral water is introduced into the electrochemical cell with two electrodes - the glass (measuring) and chlorine silver (auxiliary), connected to pH meter-millivoltmeter (pH-150), then one drop of methyl orange indicator 0.1% solution is added. The HCl solution is added from the burette, while stirring the reaction mixture on the magnetic stir bar. When titrating, the experimental data are obtained simultaneously by two methods - the acid-base titration (neutralisation) and potentiometric titration, after addition of each titrant, the solution is stirred until the constant pH value is set on the device instrument panel. Then pH value of the analysed solution is fixed according to the device (the potentiometric titration), and after the solution colour change in the presence of the indicator, the total volume of the titrant (T_VT) according to the burette (acid-base titration method) is measured. Each analysis is repeated 3 times. The results are entered into the computer program, which performs the calculation with the statistical processing.

EFFECT: decrease in cost, complexity and carrying out the express analysis of mineral waters.

1 dwg, 12 tbl