Ultrasonic supramolecular microextration of nickel (II) as N,N′-Dihydroxy-1,2-cyclohexanediimine chelates from water, tobacco and fertilizer samples before FAAS determination

A fast and efficient preconcentration method was developed based on supramolecular microextraction for separation and preconcentration of nickel(II). The composition of supramolecular solvent includes 1-decanol and tetrahydrofuran. N,N′-Dihydroxy-1,2-cyclohexanediimine was applied as chelating agent for Ni(II) as well as to facilitate the transference of the complex from aqueous sample solution to the supramolecular organic layer. The developed preconcentration method was followed by flame atomic absorption spectroscopy measurement for nickel detection. The optimum conditions for the quantitative results were at the pH between 5.5 and 6.5, and volume of 0.1% N,N′-Dihydroxy-1,2-cyclohexanediimine between 100 μL and 200 μL. The developed procedure was applicable in case of applying different matrix. The limit of detection (LOD) and the limit of quantification (LOQ) were found to be 1.3 μg L− 1 and 3.9 μg L− 1 respectively. TMDA 64.2 and TMDA 53.3 certified reference materials were used to validate the proposed procedure and the results showed good agreement. The developed method was applied for determination of Ni(II) in water, tobacco and fertilizer samples.