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A Simple Spectrophotometric Method For The Determination Of Vanadium In Real, Environmental, Biological And Soil Samples Using 2-Hydroxyacetophenobenzoylhydrazone

M.Jamaluddin Ahmed, M.Nasir Uddin, D.A.Chowdhury

A very simple, ultra-sensitive and highly selective non-extractive spectrophotometric method for the determination of trace amount of vanadium(V) using 2-Hydroxyacetophenobenzoylhydrazone(HAPBH) has been developed. 2-Hydroxyacetophenobenzoylhydrazine(HAPBH) reacts in slightly acidic (0.0005-0.025M H2SO4) 50% 1,4-dioxane media with vanadium(V) to give a yellow chelate which has an absorption maximum at 422 nm. The reaction was instantaneous and absorbance remains stable for over 48 hours. The average molar absorption co-efficient and Sandell’s sensitivity were found to be 7.70 × 104 L mol-1 cm-1 and 10 ng cm-2 of VV, respectively. Linear calibration graphs were obtained for 0.1-15 μg mL-1. The stoichiometric composition of the chelate is 1:2 (V:HAPBH). Large excess of over 60 cations, anions and complexing agents (like tartrate, oxalate, chloride, phosphate, thio-urea, SCN- etc.) do not interfere in the vanadium determination. The method was successfully used in the determination of vanadium in several Standard Reference Materials( alloys and steels) as well as in some environmental waters(potable and polluted), biological samples(human blood and urine), soil samples and complex synthetic mixtures. The method has high precision and accuracy (s = ± 0.01 for 0.5 μg mL-1).