Extraction and Determination of Vanadium in Food, Biological, Alloy, Water and Environmental Samples

A novel reagent, N,N′-diphenyl sebacoyl dihydroxamic acid (DPSDHA), has been developed for the extraction and trace determination of vanadium(V) in different matrices. The extraction behaviour of vanadium(V) from 6 M HCl medium has been systematically investigated. Key parameters such as solvent choice, reagent concentration, effect of pH and the effect of interfering ions were optimized. The vanadium—N,N′-diphenyl sebacoyl dihydroxamic acid complex forms a violet-coloured species with a maximum absorbance (λₘax) at 520 nm and a molar absorptivity of 7.96 × 103 L mol–1 cm–1. The free reagent N,N′-diphenyl sebacoyl dihydroxamic acid does not absorb at this wavelength. The complex obeys Beer’s law in the concentration range of 6.28 × 10–8 M – 1.26 × 10–6 M (0.0032–0.064 ppm). The method exhibits a limit of detection (LOD) of 6.0 × 10–7 ppm and a limit of quantification (LOQ) of 5.0 × 10–6 ppm. Ten replicate measurements of a 0.010 ppm vanadium(V) solution yielded a relative standard deviation (RSD) of 1.1%, confirming high precision. The dichloromethane extract of the vanadium complex was directly introduced into inductively coupled plasma—mass spectrometry (ICP–MS), enhancing sensitivity by 60 fold. The method was successfully applied to the analysis of standard reference materials, as well as water, biological, and environmental samples.