A solid phase extraction procedure is presented for the separation and preconcentration of trace levels of Pd(II) ion by using exfoliated graphene nanosheets (GNs). Experimental parameters such as extraction time, pH, type of eluent, sample volume and temperature were studied in detail. The Pd(II) adsorbed on the GNs was eluted with 1.5 mol L-1 sodium thiosulfite and then determined by flame atomic absorption spectrometry. The effects of potentially interfering ions on the recovery of Pd(II) were also examined. Under optimized conditions, the method provides a preconcentration factor of 100, had a linear range from 5.0 ng mL−1 to 100 ng mL−1 of Pd(II), a limit of detection 2.1 ng mL−1, and a relative standard deviation 1.1% at 20 ng mL−1 of Pd(II). The method was validated by the extraction and determination of Pd(II) in water, tea, lentil and bovine liver samples.
