A novel [2] rotaxane hydroxamic acid for the liquid-liquid extraction and determination of vanadium(V)

Abstract

A new reagent, [2] rotaxane hydroxamic acid, is reported for extraction and trace determination of vanadium(V) in nutritional and biological substrates. The extraction mechanism of vanadium from 6 M HCl media is investigated. Optimum conditions like solvent, influence of reagent and diverse ions etc on the extraction of vanadium have been examined. The overall stability constant (log β₂Ke) and extraction constant (Kex) in chloroform are 2.50 ± 0.02 and 4.0 ± 0.02  10⁻⁸ respectively. The system obeys Beer’s law in the range of 0.815-3.26 μg mL⁻¹ of vanadium(V). The molar absorptivity is 6.66  10³ L mol⁻¹ cm⁻¹ at 525 nm. The vanadium(V) complex chloroform extract has been directly inserted into plasma for ICP-AES measurements, which increases the sensitivity by 50 folds. The method is applied for determination of vanadium(V) in standard samples, sea water and environment samples.