THERMODYNAMIC STUDY OF THE (CaCl2 + Ca(NO3)2 + L-GLUTAMINE + H2O) SYSTEM USING POTENTIOMETRIC MEASUREMENTS

In this work, the thermodynamic properties of the quaternary (CaCl2 + Ca(NO3)2 + L-glutamine + H2O) system, using the potentiometric method, were reported. The potentiometric measurements were performed in mixed solvent systems containing 2.5% mass fraction of L-glutamine, over total ionic strengths from 0.0100 mol.kg−1 to 4.0000 mol.kg−1 at T = 293.2 K and P= 0.1 MPa. The Ca−ISE was prepared in our laboratory using the ionophore treated by carbon nanotubes. The Pitzer ion interaction model was used to correlate the experimental data. The unknown parameters were evaluated. There is a good consistency between the experimental results and Pitzer model.