Nitrotoluene and nitrobenzoic acid isomers were separated completely in less than 10 minutes by Kromasil C18 (200 mm x 4.6 mm i.d.), when V(CH3OH):V(H2O):V(THF) = 55:44:1 with beta-CD of 0.02 mol/L at flow rate of 2.0 mL/min (former 4 min) and 2.6 mL/min (later 6 min). Detector of UV-254 at 0.04 AUFS was used.