Analytical Sciences

Abstract − Analytical Sciences, 15(12), 1261 (1999).

A Highly Sensitive and Selective Spectrophotometric Determination of Vanadium(V) Using 6-Chloro-3-hydroxy-7-methyl-2-(2-thienyl)-4H-chromen-4-one
N. AGNIHOTRI, R. DASS and Jaswant R. MEHTA +
Department of Chemistry, Kurukshetra University, Kurukshetra-136 119, Haryana, India
A simple, rapid, highly sensitive and selective method for the extractive spectrophotometric determination of micro amounts of vanadium(V) has been worked out using 6-chloro-3-hydroxy-7-methyl-2-(2-thienyl)-4H-chromen-4-one (CHMTC) as a complexing agent in a weakly acidified (HCl, pH 0.84 - 1.09) medium. The greenish-yellow complex is quantitatively extractable into carbon tetrachloride, and shows maximum absorbance at 417 - 425 nm. The method obeys BeerÕó law up to 0.9 mg V ml -1 , having molar absorptivity and SandellÕó sensitivity of 8.26«±0 4 dm 3 mol -1 cm -1 and 0.0006 mg V cm -2 , respectively. As many as 39 cations and 14 anions and/or complexing agents do not interfere. The method has good reproducibility and can be satisfactorily applied to the determination of vanadium in steels, reverberatory flue dust and water samples. (Keywords: Vanadium, extraction, 6-chloro-3-hydroxy-7-methyl-2-(2-thienyl)-4H-chromen-4-one, spectrophotometry)