Methyl tertiary butyl ether (MTBE) is a widely used gasoline oxygenate. Contamination of MTBE and its major degradation product tertiary butyl alcohol (TBA) in groundwater and surface water has received great attention. However, removal of these contaminants from water is a problem. In this research, the liquid-liquid equilibrium (LLE) data were measured for the systems MTBE + water + salts at 298.15 K. The salts used are CaCl2, MgCl2, NaCl, and KCl. In order to selecting a suitable salt for better separation, the partition coefficient and the selectivity factor of MTBE in these systems were calculated. A two-parameter equation was used for the correlation of the experimental tie-line data. Using this model the salting-out power of the salts was determined. Good agreement was obtained with the experimental tie-line data with this model. (c) 2007 Elsevier B.V. All rights reserved.