Dispersive Liquid-Liquid Microextraction Based on Solidification of Floating Organic dro‎p as an Efficient Preconcentration Method for Spectrophotometric Determination of Aluminium

A rapid, simple, and sensitive dispersive liquid-liquid microextraction based on solidification of floating organic drop (DLLME-SFOD) method coupled with UV-Vis spectrophotometry has been applied for the extraction and determination of trace amounts of aluminium. The aluminium was extracted from the aqueous media containing aluminon and cetyltrimethylammonium bromide (CTAB). After rapid injection of the 1-undecanol mixture as the extraction solvent and ethanol as the disperser solvent into the sample, a cloudy mixture was formed and the complex was extracted into 1-undecanol. After centrifugation and cooling in an ice bath, the solidified organic drop on top of the solution was transferred into a vial which was melted at room temperature. Then, the organic phase containing the metal complex was diluted with ethanol and was transferred into a microcell for quantification. The pink chelate exhibits maximum absorbance at 535.0 nm, and with a preconcentration factor of 100.0 obeys Beer’s law over the concentration range of 1.0-15.0 μg l-1 of aluminium. The limit of detection of 0.14 μg l-1 and a relative standard deviation of 1.8% at 3.0 μg l-1 (n = 6) were obtained. The procedure was successfully applied for the determination of aluminium in tea and water samples.