Solidified floating organic drop microextraction and spectrophotometric determination of vanadium in water samples

Solidified floating organic drop microextraction (SFODME) was used as a sample preparation method prior to spectrophotometric determination of trace amounts of vanadium in water samples. 8-Hydroxyquinoline (oxine) was used as the chelating agent. The main parameters affecting the performance of SFODME, such as pH, concentration of oxine, extraction time, sample and organic phase volume, extraction temperature, and the nature of the organic solvent, were optimized. Under the optimized conditions, an enhancement factor of 38, detection limit of 0.97 mu g L-1, and good relative standard deviation of +/- 3.9% at 10 mu g L-1 were obtained. The method was successfully applied to the determination of vanadium in tap water, well water, river water, and sea water. The accuracy of the method was assessed through a recovery experiment and independent analysis by graphite furnace atomic absorption spectrometry.