Novel Hg2+-imprinted polymers based on thymine-Hg2+-thymine interaction for highly selective preconcentration of Hg2+ in water samples

A novel functional monomer T-IPTS, 3-isocyanatopropyltriethoxysilane (IPTS) bearing thymine (T) bases, was synthesized for imprinting Hg2+. Then a novel Hg2+ ionic imprinted polymers (IIPs) based on thymine-Hg2+-thymine (T-Hg2+-T) interactions, i.e. Hg-IIPs-T, were prepared by sol-gel process for the first time in this work. The Hg-IIPs-T exhibited excellent selectivity towards Hg2+ over Cd2+, Zn2+ Pb2+, Co2+, Mn2+, Mg2+ and Ca2+, due to the specific T-Hg2+-T interactions with high selectivity and high affinity. Accordingly, Hg-IIPs-T were used as solid-phase extraction (SPE) sorbents for preconcentration of trace Hg2+ in water samples, and satisfactory recoveries ranging from 95.2 to 116.3% were obtained. Also, under optimized conditions, preconcentration factor and detection limit were achieved of 200 and 0.03 mu g L-1, respectively. The IIPs-T-SPE proved to be a rapid and high-effective cleanup and enrichment method for trace Hg2+ in water samples. More importantly, these results indicated that devising and synthesizing new functional monomers tailor-made for template would become a general promising way to improve the selectivity and stability of IIPs. 2012 Elsevier B.V. All rights reserved.