A modified catalytic-photometric method for the determination of vanadium in chloride rich hydro-geochemical samples

The vanadium content in chloride rich hydrogeochemical samples has been determined through a modification in the existing standard gallic acid oxidation method which has severs interference problem from halides. The modification incorporates a preliminary fume-drying of the sample aliquot with a mixture of perchloric and sulphuric acids. This ensures total removal of halides and hence their interference. The estimation is completed as per the standard method after taking the sample in 10 ml of 1% nitric acid. Also mercuric nitrate addition which forms a part of the standard procedure to prevent halide interference, is also dispensed with keeping in View the toxic nature of mercury. The method has been tried on a number of samples having varying chloride content. The results obtained compare well with the standard PAR method. The method can be used to determine vanadium down to 1 ppb. The relative standard deviation obtained for vanadium contents in the range 400-10 ppb is in the range 4-8.2%. (C) 1998 Elsevier Science B.V. All rights reserved.