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.

Keywords:

• Alloy steels
• Determination of vanadium
• Foodstuffs
• HMBATSC
• Soil and biological samples
• Spectrophotometry

Notes

∗Average of five determinations.

∗Average of five determinations.

^a masked with 1760 µg of ascorbic acid.

^b masked with 1400 µg of tartrate.

^a In the presence of 1760 µg of ascorbic acid.

^b 1400 µg of tartrate.

^a Mean±standard deviation (n = 5).

^b Tabulated F-value for (4,4) degrees of freedom at P(0.95) is 5.73.

^c Tabulated t-value for 8 degrees of freedom at P(0.95) is 2.66.

^d Neogadine Elixir®, Raptakos Brett&Co. Ltd., India (each 15 ml contains Iodised peptone 29 mg, magnesium chloride 20 mg, magnesium sulfate 4 mg, sodium metavanadate 0.66 mg, zinc sulfate 6 mg, pyridomine HCl 0.75 mg, cyanocobalamin 0.5 µg, nicotinamide 10 mg, alcohol (95%) 0.95 ml, total alcohol 6% (v/v), vanadium taken 7.89 ppm.

^e Gave no test for vanadium.