Development of a Pre-concentration Method for Nickel in Chocolate Samples using Magnetic Dispersive Solid- phase Extraction Followed by Flame Atomic Absorption Spectrometry

In this study, magnetic dispersive solid-phase extraction (MDSPE) combined flame atomicabsorption spectrometry (FAAS) was used as a new method for the analysis of nickel preconcentration in chocolate samples. A suitable mixture of magnetic adsorbent 1(2,3-dihydroxypropyl)-1,4diazabicyclo[2.2.2] octanylium [DABCO-PDA] and chloro-functionalized Fe3O4 nanoparticles (NPs) with chelating agent dimethylglyoxime (DMG) was added into an aqueous solution. Adsorption behaviors of Ni (II) ion on Fe-[DABCO-PDA] NPs were studied. Finally, the main parameters affecting the extraction and determination of the analysis were investigated in detail.According to the findings, the analyte was quantitatively holed on Fe-[DABCO-PDA] NPs in pH 8, eluted totally with 3 ml of ethanol HNO3 2% (v/v), and adsorbed about 50 mg. Under the optimal experimental conditions, the detection limit (LOD) was 0.18 µg Kg-1, with a standard deviation of1.8-4% (n=5). The linear working range of the calibration curve was 1-250 µg Lit-1 and the recovery values ranged from 92 to 97% for all samples. The proposed method was fast, simple, effective and high tolerability to the presence of the ions. Moreover, high sensitivity, better recovery, and the use of environmentally friendly solvents are the other advantages of this technique.