Vortex-assisted ionic liquid microextraction coupled to flame atomic absorption spectrometry for determination of trace levels of cadmium in real samples

A simple and rapid vortex assisted ionic liquid based liquid–liquid microextraction technique (VALLME) was proposed for preconcentration of trace levels of cadmium. According to this method, the extraction solvent was dispersed into the aqueous samples by the assistance of vortex agitator. Cadmium preconcentration was mediated by chelation with the 8-hydroxyquinoline (oxine) reagent and an IL, 1-octyl-3-methylimidazolium hexafluorophosphate ([Omim][PF6]) was chosen as the extraction solvent to extract the hydrophobic complex. Several variables such as sample pH, concentration of oxine, volume of [Omim][PF6] and extraction time were investigated in details and optimum conditions were selected. Under the optimum conditions, the limit of detection (LOD) was 2.9 μg L^-1 for Cd () and relative standard deviation (RSD%) for five replicate determinations of 125 μg L^-1 was 4.1%. The method was successfully applied to the determination of cadmium in tap water, apple and rice samples.