An inductively coupled plasma mass spectrometer (ICP-MS) coupled with ultrasonic nebulization was used as a liquid chromatographic detector for the determination of vanadium species. In this study, ionic vanadium species (V(IV) and V(V)) were separated by reversed-phase liquid chromatography (LC) with a C8 column as the stationary phase and 3 mmol l(-1) EDTA, 0.5 mmol l(-1) tetrabutylammonium phosphate and 12% (v/v) methanol solution (pH 6.5) as the mobile phase. Effluent from the LC column was delivered to the ultrasonic nebulization system and the ICP-MS for the determination of vanadium. Repeatability of peak height was better than 6%. The limits of detection for V(IV) and V(V) were 0.025 and 0.041 ng ml(-1) V, respectively, based on peak height. The concentrations of vanadium species have been determined in open ocean seawater reference material NASS-4, nearshore seawater reference material CASS-3 and riverine water reference material SLRS-3. (C) 1997 Elsevier Science B.V.