A Rapid, Simple, and Sensitive Spectrophotometric Determination of Traces of Vanadium (V) in Foodstuffs, Alloy Steels, and Pharmaceutical, Water, Soil, and Urine Samples

Abstract

A rapid, simple, sensitive, and selective spectrophotometric method is investigated for the determination of traces of vanadium (V) in foodstuffs, alloy steels, and pharmaceutical, water, soil, and urine samples in aqueous DMF medium. The metal ion forms a green colored complex with 2-hydroxy-3-methoxy benzaldehyde thiosemicarbazone (HMBATSC) in an acidic buffer of pH 6.0. The green colored solution, having an absorbance maximum at 380 nm, is stable for more than 72 hours. Beer's law is obeyed in the range of 0.051–2.037 µg ml−1. The molar absorptivity and Sandell's sensitivity of the method are found as 2.75 × 104 l mol−1 cm−1 and 0.0018 µg cm−2, respectively. The green colored complex has 1:2 [V(V)-HMBATSC] stoichiometry. The stability constant of the complex is determined as 3.267 × 1011 by Job's method. The optimum reaction conditions and other analytical parameters are studied. A sensitive and selective second-order derivative spectrophotometry has also been proposed for the determination of V(V). The interference of various cations and anions are studied. The present method is successfully applied to the determination of vanadium (V) in foodstuffs, alloy steels, and pharmaceutical, water, soil, and urine samples.