Determination of trace vanadium in natural waters by a combined ion exchange—catalytic photometric method

A sensitive, selective and simple method is described for the determination of trace vanadium in natural waters. Vanadium is separated and concentrated by a combined cation- and anion-exchange procedure in 0.05 M HCl—0.1 % H₂O₂ media, and determined by the catalytic method based on the oxidation of gallic acid by bromate. The proposed method is applied to the analysis of natural waters. The relative standard deviations are 3.9 % for 0.8 p.p.b. of vanadium in river water and 3.2 % for 1.9 p.p.b. of vanadium in lake water (surface). As little as 0.03 p.p.b. of vanadium can be determined in samples of 100 ml or less.