Reactive extraction using supercritical carbon dioxide (scCO(2)) and tri-n-octylamine (TOA) was evaluated as a separation method of succinic acid from an aqueous solution. The reactive extraction of succinic acid was performed at varying initial acid concentrations in aqueous solution (0.07-0.45 mol.dm(-3)), temperature (35-65 degrees C) and pressure (8-16 MPa). The succinic acid separation was conducted in both batch mode and semi-continuous mode. The highest reactive extraction efficiency of approx. 62% was obtained for the process conducted in semi-continuous mode at 35 degrees C and 16 MPa for the initial acid concentrations in aqueous phase of 0.39 mol.dm(-3).