Selective Solid-phase Extraction of Cu2+ by a Novel Cu(II)-imprinted Silica Gel

A new Cu(II)-imprinted salen functionalized silica gel adsorbent was synthesized by surface imprinting technique and was employed as a selective solid phase extraction material for Cu2+ removal from aqueous solutions. The samples were characterized by FT-IR, (HNMR)-H-1, (CNMR)-C-13, CHNS and DTG techniques. The BET surface area of the silica gel was also determined. The adsorbent was then used for removal of Cu2+ from aqueous solutions under different experimental conditions. It was concluded that the synthesized imprinted silica gel had higher selectivity and capacity compared to the non-imprinted silica gel and the maximal adsorption capacity of 67.3 and 56.5 mg.g(-1) was obtained respectively for ion-imprinted and non-imprinted adsorbents. The relative selectivity factor () of 50.32 and 31.94 was obtained respectively for Cu2+/Ni2+ and Cu2+/Zn2+ pairs. The dynamic adsorption capacity of the imprinted adsorbent was close to the static adsorption capacity due to the fast kinetic of adsorption. Furthermore, the ion-imprinted adsorbent was recovered and repeatedly used and satisfactory adsorption capacity with acceptable precision was obtained. Each experiment was repeated at least for three times and the mean and the standard deviation for each measurement were calculated. The applicability of the method was examined for Zayandehrood water as real sample. Acceptabe standard deviation was obtained.