The requirements for the removal of volatile organic compounds in processes are becoming more stringent. Process designs to accomplish the removal of volatile organic compounds require knowledge of the infinite dilution behavior in water. This can be estimated by extrapolating finite phase equilibrium data into the infinite dilution region. However, this is solution model dependent; i.e., different models describing the same acetone + water data predict gamma(infinity) which differ by a factor of 3. The consequence is predicted tray requirements up to 3 times different for the same separation. More reliable infinite dilution activity coefficients based on experimental data are required for reliable process design. One method is to estimate the slope (dP/dx)(x=0) by measuring (dP/dx)(x>0) at low compositions and extrapolating to infinite dilution. Ebulliometric methods are subject to temperature gradients and pressure fluctuations. Conventional static methods suffer from the presence of noncondensable chemicals. Both affect the slope and, thus, gamma(infinity) estimates. This paper presents a modified static method. A large, calibrated vapor space minimizes the impact of noncondensable chemicals. The degassed solute is micrometered incrementally into the cell containing water. Experimental design methods testing the impact of the number and volume of the metered solute verify the accuracy and precision of the resultant gamma(infinity) values. Results for acetone are reported and compared to literature values. The comparison verifies the validity of the experimental method.