Measurement of activity coefficients of amino acids in aqueous electrolyte solutions: experimental data for the systems (H2O+NaBr+glycine) and (H2O+NaBr+l-valine) at T=298.15 K

Measurement and modeling of mean activity coefficients of NaBr and amino acid in (sodium bromide+potassium phosphate+glycine+water) system at T (298.15 and 308.15)K

“…Our group has recently reported data for the activity coefficients of amino acids at various electrolyte solutions [19][20][21]. The present study is a natural continuation of the previous works, and explores the effect of presence of another electrolyte in the mixture of electrolyte and amino acid.…”

“…The experimental set-up resembles that of [20]. When the bromide ISE is used as reference electrode for the sodium ISE, the liquid-junction potential can be eliminated [19].…”

“…The present study is a natural continuation of the previous works, and explores the effect of presence of another electrolyte in the mixture of electrolyte and amino acid. The activity coefficient of glycine in aqueous electrolyte solutions of (NaBr + K 3 PO 4 ) is determined and compared with those obtained in the previous work for the (glycine + NaBr + water) mixtures [20]. No previous study has reported experimental data on the effect of another electrolyte on the activity coefficient of an amino acid in aqueous solution, already containing a single electrolyte.…”

“…As studies with different ion selective electrodes have shown, deviations from a Nernstian response [13][14][15][16][17][18][19][20], for the sake of generality instead of the Nernstian slope of electrodes RT/F = 51.38 mV at T = 298.15 K, the general slope S in equation (4) is used. It is seen from equation (4) that, the potential of the reference electrode in equation (2) cancels out when taking the difference of measured potentials in an electrochemical cell in which the potential of the cation and the anion selective electrode are directly read one against the other.…”

Modeling and prediction of activity coefficient ratio of electrolytes in aqueous electrolyte solution containing amino acids using artificial neural network

“…Form search in literature for correlative relations of mean ionic activity coefficient ratio [19][20][21][22][23][24][25][26][27][28][29], we found that the electrolyte molalities are the key parameters in correlating of experimental data, so the electrolyte molality (m s ) is used as the input parameter. On the other hand the effect of cation and anion diameters is very important in evaluation of activity coefficients of electrolyte solutions [5].…”