Abstract: In small quantities, certain heavy metals are nutritionally essential for a healthy life, while at higher levels of concentration their presence causes problems due to increased toxicity. For this reason, the development of reliable methods for removal and determination of heavy mrtals has been a very active area of research [1,2]. In this work, a solid phase extraction procedure was presented for separation and preconcentration of trace levels of Cu (II) ion using amino functionalized Fe3O4 graphene nanocomposite. Experimental parameters such as pH, type of eluent solvent, sample volume, temperature, amount of nanocomposite and ultrasonic time were studied in detail. 50 mL copper ion(10 Pg L-1 ) was add to 0.005g nanocomposite at pH6.0 then the mixtures in the flasks were ultrasonicated for 10 minutes to guarantee a good dispersion of nanocomposite and then assemble the nanocomposite by magnet and copper ion desorbed from nanocomposite with 0.5mL HCl 0.1M and then 0.5mL sample directly injected into the flame atomic absorption spectroscopy. The effect of potentially interfering ions on the recovery of Cu (II) was also examined. Under optimized conditions, the method provided a enhancement factor of 95.08, had a linear range from 1.0- 100 ng mLí1 of Cu (II), a detection limit of 0.9 ng mLí1 and a relative standard deviation 1.23 % at 10 ng mLí1 of Cu (II). The method was validated by the extraction and determination of Cu (II) in eggplant, red lentil, and mushroom samples.
