A Novel Ion-imprinted Polymer Based on Multi-walled Carbon Nanotubes for Solid Phase Extraction of Pd(II)

A novel Pd(II) ion-imprinted polymer (Pd(II)-AAP-IIP@VMWCNTs) was constructed by using 2-( N -allyl)aminopyridine (AAP), vinyl functionalized multi-walled carbon nanotubes (VMWCNTs), ethylene glycol dimethacrylate (EGDMA) and Na 2 PdCl 4 as functional monomer, carrier, cross-linker and template ions, respectively. The structure, morphology, adsorption property and applicability as adsorbent in solid phase extraction were characterized by Fourier transform infrared (FTIR) spectroscopy, transmission electron microscopy (TEM), scanning electron microscopy (SEM), binding experiment and solid phase extraction (SPE) experiment, respectively. The equilibrium adsorption capacity and imprinting factor of Pd(II)-AAP-IIP@VMWCNTs for Pd(II) were found to be 9.053 mg/g and 3.46, respectively. The SPE column packed with Pd(II)-AAP-IIP@VMWCNTs displayed good adsorption selectivity to Pd(II). The adsorption rate and extraction rate of this column to Pd(II) were more than 90% and 74%, but below 40% and 15% to the other coexisting ions under the optimized SPE conditions. The obtained Pd(II)-AAP- IIP@VMWCNTs-based SPE method could be combined with inductively coupled plasma optical emission spectroscopy (ICP-OES) for determination of Pd(II) in environmental water. The recoveries were in the range of 87.2%–91.6% with the relative standard deviations of 2.5%–6.8%.