The separation of organic compounds using reactive extraction (combination of extractant + solvent system) has a great potential in the near future but limits its application in the extractive fermentation system because of the toxicity of solvents. Here, a study is performed for the recovery of nicotinic acid using a biocompatible system comprising a tertiary amine, tri-ndodecylamine (TDDA), a high molecular weight modifier, oleyl alcohol, and an inert diluent, n-dodecane. At first, the effect of oleyl alcohol (modifier or active solvent) is studied at fixed TDDA concentration (0.1 v/v) with n-dodecane. Oleyl alcohol (increased from 0.06 to 0.62 w/w) enhanced the extraction efficiency significantly (from 15.46% to 67.25%). To have a control over the physical properties of the extraction system, further extraction studies are performed using TDDA (9.94 X 10(-5) to 4.91 x 10(-4) mol.kg(-1)) dissolving it in n-dodecane and oleyl alcohol mixture maintained at a ratio of 2:1 w/w, and varying nicotinic acid concentration from 0.022 to 0.122 mol.kg(-1). The highest distribution of acid is observed to be 1.87 with 4.91 X 10(-4) mol.kg(-1) of TDDA at 0.057 mol.kg(-1) acid concentration and at 301 K. To deduce the extraction mechanism, the stoichiometric coefficient of complex formation (m), and equilibrium constant are determined. The temperature (varied between 301 and 333 K) effect is studied on the distribution coefficient, and used to determine thermodynamic parameters (Delta H degrees = -133.63 kJ.mol(-1); Delta S degrees = -414.69 J-mol(-1).K-1).