Synthesis, adsorption and selectivity studies of N-propyl quaternized magnetic poly(4-vinylpyridine) for hexavalent chromium.

The ability of solid N-propyl quaternized magnetic poly(4-vinylpyridine) for the extraction of chromium(VI) in aqueous solutions was investigated. For the synthesized Cr(VI) magnetic polymers, the optimum pH obtained was 4 for both the magnetic ion imprinted polymer (IIP) and the corresponding non-ion imprinted polymer NIP. The amount of the adsorbent which gave the maximum adsorption was determined to be 20 and 65 mg for the magnetic IIP and NIP, respectively. A Cr(VI) concentration which was adsorbed maximally was 5 mg L(-1) which was therefore taken as the optimum. The maximum adsorption capacities for the magnetic polymers were 6.20 and 1.87 mg g(-1) for the magnetic IIP and NIP, respectively. The optimum time for the adsorption of the Cr(VI) analyte was determined as 40 min. The prepared magnetic ion imprinted polymer showed good selectivity towards Cr(VI). The order of selectivity of the investigated anions followed the sequence: Cr2O7(2-)>SO4(2-)>F(-)>NO3(-).