Preconcentration of Gadolinium Ion by Solidification of Floating Organic Drop Microextraction and Its Determination by UV-Vis Spectrophotometry

A solidified floating organic drop microextraction (SFODME) combined with UV-Vis spectrophotometry was applied for preconcentration and determination of Gd(III). In this study, Morin (3, 5, 7. 2’, 4’ pentahydroxy flavone) as a suitable ligand and 1Dodecanol as extraction solvent were used. Following the extraction Gd-Morin complex, the extraction solvent was transported to a spectrophotometer for determination of Gadolinium ion at the absorption wave length of 440 nm. The main affecting factors in the performance of SFODME such as pH, concentration of Morin, extraction time, stirring rate and sample volume were investigated and optimized. Under the optimum conditions, the enrichment factor of 23, linear dynamic range of 80-900 μg L-1 with correlation of determination (R2>% 99) and limit of detection of 172μg L-1 were obtained for determination of Gd(III). The relative standard deviation (n = 5) for 150 μg L−1 of Gd(III) (sample volume 4.0mL) was ±2.17%. The method was successfully applied for preconcentration and determination of Gd(III) in water samples.