Liquid-liquid extraction, separation and preconcentration, membrane transportation and ICP-AES determination of vanadium with dibenzo-18-crown-6

Abstract

Dibenzo-18-crown-6(DB18C6) is used for the liquid-liquid extraction and membrane transporation of vanadium(V).Vanadium is extracted with DB 18C6 in 3.0 <i>M </i>HCl medium using dichloromethane as solvent which forms a colourless complex (λ_max 285 nm). The complex obeys Beer's law in the range of 4.25-93.5 ng mL^-1. The dichloromethane extract is

directly inserted into plasma for inductively coupled plasma atomic emission spectrophotometric (ICP-AES) estimation of vanadium, which enhances the sensitivity several folds and the limits for estimation is 0.2-5.0 ng mL^-1 with detection limit 0.05 ng mL^-1. The overall formation constant (logβ₂<i>K</i>ʹ_c) and extraction constant (<i>K</i>_cx) calculated are 22.20 and 1.8×10^-14 at 25°C, respectively. Vanadium is preconcentrated and determined in sea water, standard samples and environmental samples.