Spectrophotometric determination of trace levels of nickel in water samples after dispersive liquid liquid microextraction using 2,2'-furildioxime as the complexing agent.

A new method of dispersive liquid-liquid microextraction (DLLME) combined with UV-Vis spectrophotometry was proposed for the determination of trace nickel using 2,2'-Furildioxime as chelating and spectrophotometric reagent. In the proposed approach chloroform and ethanol were used as extraction and dispersive solvents, respectively. Some factors influencing the extraction efficiency of nickel and its subsequent determination were studied and optimized, such as the extraction and dispersive solvent type and volume, pH of the sample solution, extraction time and ionic strength. Under the optimal conditions, the calibration curve was linear within the range of 5-180 µg L-1 of nickel with R2 = 0.9960. Limit of detection (3Sb/m) was 0.6 µg L-1 in the original solution and the relative standard deviation for ten replicate determination of 100 µg L-1 nickel was 2.9%. The proposed method has been applied for the determination of nickel in various water samples with satisfactory results.