Evaluation of the vapour pressure of aqueous NaCl-sorbitol solution and correlation of the water activity on composition and temperature

• Measurement of the vapour pressure of aqueous NaCl-sorbitol solutions.
• Correlation of water activity on a wide range of compositions and temperature.
• Dependence on temperature of the parameters in the range (293 ≤ T/K ≤ 348).

The vapour pressure over water (1) sodium chloride (2) and sorbitol (3) ternary solutions of different concentrations (mi ≤ 4, i: 2,3) was measured at 338 K and 348 K. Starting from these data, the values of the experimental water activity (a1) were calculated. These data and those obtained for other authors at 293 K, 298 K and 308 K were correlated with a previously developed equation for a1(m2, m3). Thus, the equation parameters and their corresponding temperature dependences were obtained. The corresponding root mean square deviation was evaluated, being in all cases less than 0.005.