Magnetic solid-phase extraction and Uv/vis Spectrophotometric determination of trace amount of Copper in vegetable and fruit samples after preconcentration of its Pentetate complex

Core-shell structure Magnetite@polydopamine (Fe3O4@PDA) nanoparticles have been successfully synthesized and were characterized by FT-IR, TEM, FE-SEM, XRD, EDX, Raman Spectroscopy, VSM and Zeta potential. The effects of the different parameter on copperpentetate complex (CuDTPA) sorption on Fe3O4@PDA were investigated by using Box-Behnken design for Spectrophotometric determination of trace amount of Copper in vegetable and fruit samples after preconcentration of its Pentetic complex. Under optimal experimental conditions, L.R., LOD, and LOQ of Cu (II) were 2-700 µg.L-1, 0.0146 µg.L-1 and 0.0487 µg.L-1 respectively. The Preconcentration Factor 100 was obtained.  Low relative standard deviations (RSD=0.7 %) for 10 replicates are achieved. The method was applied to the determination of trace amount of Cu (II) in food samples and the results showed that no significant difference between the proposed method and Flame Atomic Absorption Spectroscopy.