The separation and preconcentration of trace vanadium from an aqueous solution for a graphite furnace atomic-absorption spectrometric (GF-AAS) determination was studied using silica gel loaded with trioctylmethylammonium cloride (Capriquat). A sample solution containing V was adjusted to pH 6.0. The solution was then passed through 1.0g of Capriquat loaded in a silica gel column at a flow rate of 10 ml min^-1. The V collected on the Capriquat-loaded silica gel on the column was eluted with 10 ml of 0.5 M perchloric acid, and then determined by GF-AAS. In this method, over 99% of the V was adsorbed at about pH 6.0. The calibration curve was linear from 0.05 to 2.5 μg/l of V. The proposed method has been applied to the determination of V in river water and seawater samples.