A spectrophotometric assay method for vanadium in biological and environmental samples using 2,4-dinitrophenylhydrazine with imipramine hydrochloride.

A simple, rapid, and sensitive method involving the interaction of 2,4-dinitrophenylhydrazine with imipramine hydrochloride in presence of vanadium (V) in sulfuric acid medium has been proposed for the determination of vanadium. The purple-colored product developed showed an absorption maximum at 560 nm and was stable for 24 h. The working curve was linear over the concentration range of 0.1-2.8 μg ml( - 1), with sensitivity of detection of 0.0124 μg ml( - 1). Molar absorptivity and Sandell's sensitivity were found to be 2.6 × 10(4) l/mol cm and 0.0039 μg cm( - 1), respectively. The accuracy of the proposed method was assessed by Student's t test and variance ratio F test, and the results were on par with the reported method. The method was successfully used in the determination of V in water, human urine, soil, and plant samples, and it was free from interference by various concomitant ions.