Solidified floating organic drop microextraction for speciation of Se (IV) and Se (VI) in water samples prior to electrothermal atomic absorption spectrometric detection

A simple and fast solidified floating organic drop microextraction (SFODME) method is suggested for the speciation of Se (IV) and Se (VI) in water samples prior to electrothermal atomic absorption spectrometric (ETAAS) detection. For that purpose, 1-phenylthiosemicarbazide (PTC) was used as chelating agent and undecanol was used as extraction solvent. The pH of solution, extraction solvent volume, amount of ligand, effect of time for complex formation, and effect of possible foreign ions were also evaluated for quantitative and effective extraction of analyte. Under optimized parameters, detection limit (0.19 $\mu $g L$^{-1})$, limit of quantification (0.60 $\mu $g L$^{-1})$, relative standard deviation (4.6%), linear range (0.60-24 $\mu $g L$^{-1})$, relative error (-4.3%), and enrichment factor (53) were calculated, respectively. The accuracy of the SFODME method was confirmed with analysis of reference material (LGC 6010 Hard drinking water). The presented method was applied to water samples.