Multi-Walled Carbon Nanotubes Magnetic Composite as an Adsorbent for Preconcentration and Determination of Trace Level Vanadium in Water Samples

Abstract

Magnetic solid phase microextraction (m-SPME) is a well-defined strategy for the preconcentration and separation of hydrophobic species from aqueous samples without the use of toxic organic solvents. This work identifies a new analytical procedure for trace level vanadium(V) by inductively coupled plasma mass spectrometry coupled to magnetic solid phase microextraction. The procedure is based on the preconcentration of the V(V)-H2O2-4-(2-pyridylazo)resorcinol complex. Magnetic Fe3O4 nanoparticles decorated multi-walled carbon nanotubes as an adsorbent were investigated systematically. The calibration curve obtained by using m-SPME for vanadium(V) was linear from 0.011 to 10 mu g/L-. The method detection limit was found to be 1.5 ng/L. The m-SPME method was applied to the assay of vanadium in a certified reference water sample and the result was in total balance with the declared value. Finally, the proposed method was applied to the determination of vanadium in real water samples.