Thiophene-2-hydrazide as a reagent for the spectrophotometric determination of vanadium in aqueous solution

Abstract

A new chromogen, thiophene-2-hydrazide, for the determination of trace amounts of vanadium in aqueous solution has been developed. The intense yellow, water-soluble, stable and binary complex, formed in acidic medium, is suitable for the determination of 0.5–5 p.p.m. of vanadium ion, with a molar absorptivity of 12.1 × 10³ mol^–1 cm^–1, at 410 nm, relative error –0.6 to +4.0% and relative standard deviation 0.3–0.8%, depending on the concentration level of the determinant. Moreover, the colour formation is very fast. Interferences due to foreign ions have been examined.