Liquid-liquid equilibrium (LLE) data for the ternary system of (2-pentanone + catechol + water) and (mesityl oxide + catechol + water) was measured under atmospheric pressure at T = (298.2, 318.2 and 333.2) K The distribution coefficients and separation factors were employed to assess the efficiency of extracting catechol from water. The nonrandom two liquid and universal quasichemical models were applied to correlate the LLE data, and the corresponding binary interaction parameters were obtained. The topological analysis of LLE correlation was used to confirm that the parameters satisfy the Gibbs stability criteria.