The extraction of lactic acid was done by tripropylamine (TPA) dissolved in seven single solvents (isoamyl alcohol, heptan-1-ol. hexan-1-ol. octan-1-ol, nonan-1-ol. decan-1-ol, and dodecanol). All measurements were carried out at 298.15 K. The extent to which the organic phase may be loaded with lactic acid is expressed as loading ratio, Z its value extraction efficiencies. E, and overall particular distribution coefficients, D, were calculated. Equilibrium complexation constants for(acid:amine) (1:1), (1:2) have been determined according to Bizek's approach. The maximum removal of lactic acid accomplished was about 81% with isoamyl alcohol having 1.935 mol dm(-3) initial concentration of TPA. All of the obtained data have been correlated by linear solvation energy relationship (LSER) model. LSER model results were compared with the experimental results and well agreement between them was observed. Regression coefficient (R-2) of LSER model is 0.972. (C) 2009 Elsevier B.V. All rights reserved.