D/H AND ¹⁸O/¹⁶O PARTITIONING BETWEEN WATER LIQUID AND VAPOR IN THE SYSTEM H₂O-Na-K-Mg-Ca-Cl-SO₄ FROM 0 TO 350°C

Oxygen and hydrogen isotope partitioning between liquid water and water vapor has been precisely determined by means of direct mass-spectrometric measurements of isotopic abundances of the two phases from room temperature to 350°C. Measurable changes in the liquid-vapor partitioning were observed upon the addition of salts (NaCl, KCl, MgCl₂, CaCl₂, Na₂SO₄, and MgSO₄) to the system. Our results of isotope partitioning for the isotopic mixtures and the literature data of vapor pressure measurements of separate isotopic waters agree well for pure water, but show notable discrepancy for salt solutions.