Supramolecular solvent-based dispersive liquid phase microextraction for spectrophotometric determinate of Ni(II) with 1-(2-pyridylazo) 2-naphthol (PAN)

In this study a supramolecular-based dispersive liquid phase extraction [1,2] has been developed for the separation and preconcentration of Ni(II) for its spectrophotometric determination by PAN reagent. The method is based on the complextion of Ni(II) with PAN and subsequent extraction of formed hydrophobic complex into the fine droplets of dispersed supramolecular solvent phase. The selected Supramolecular (SM) solvent was made up of the reversed micelles of decanoic acid dispersed in a continuous phase of tetrahydrofuran ( THF)-water [3]. The driving forces for the extraction were hydrophobic, hydrogenbonding, and π-cation interactions between the analytes and the Supramolecular. The effect of experimental parameters such as type and volume of supramolcular solvent, amount of reagent, PH, sample volume, salt effect, extraction time were investigated and optimized. Also the effects of potential interfering species were examined. Under optimum experimental conditions Ni(II) can be determined in the linear range of 1- 50 ng/ml (R2=0.9969) with a detection limit of 0.27 ng/ml. A preconcentration factor of 66 was obtained and the relative standard deviation for 20 ng/ml (n=5) was found to be 3.7%. Also the presented method was successfully applied for determination of Nickel in water samples. This method allows quick and simple microextraction of Ni(II) with minimal solvent consumption, while delivering accurate and precise data.