Separation and preconcentration of palladium using modified multi-walled carbon nanotubes without chelating agent

A solid phase extraction procedure is presented for the separation and preconcentraton of trace levels of Pd(II) ion by using oxidized multiwalled carbon nanotubes (MWCNTs). Experimental parameters (pH, type of eluent, sample volume and flow rate of sample solutions) were studied in detail. The Pd(II) adsorbed on the MWCNTs was eluted with 3.0 M nitric acid 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 165, has a linear range from 1.0 ng mL(-1) to 200 ng mL(-1) of Pd(II), a detection limit of 0.3 ng mL(-1), and a relative standard deviation 5.3% at 50 ng mL(-1) of Pd(II). The method was validated by the extraction and determination of Pd(II) in water, fly ash, and road dust samples.