A new ion-selective cross-linked poly(vinylimidazole-co-ethylene glycol dimethacrylate) prepared via a double-imprinting process was developed for the recognition and preconcentration of Pb2+ from water samples. The sorbent was characterized by FT-IR, SEM, TGA and textural data. The maximum dynamic sorption capacity of Pb2+ was 42.04mg Pb2+g-1 of the double-imprinted polymer. The sorption kinetics data were described by a pseudo-second-order model. The double-imprinted polymer exhibited a higher sorption efficiency of Pb2+ than the blank polymer (non-imprinted polymer). The preconcentration procedure involved the loading of a Pb2+ solution at pH 7.25 through 40.0mg of the double-imprinted polymer packed in a mini-column at 5.0mLmin-1. The selective efficiency of proposed method for the Pb2+ preconcentration was assured by competitive sorption using different proportions of Pb2+/cations and Pb2+/anions. An analytical curve was obtained in the range 0.0-300.0μgL-1 (r=0.999) and a limit of detection of 2.46μgL-1 was obtained. The preconcentration factor was found to be 21, the consumptive index 0.95mL and the concentration efficiency 5.25min-1. The preconcentration method was successfully applied to the Pb2+ ions determination in different kinds of water samples with high recovery values (91.3-108.9%).
Tarley, C. R. T., Corazza, M. Z., Somera, B. F., & Segatelli, M. G. (2015). Preparation of new ion-selective cross-linked poly(vinylimidazole-co-ethylene glycol dimethacrylate) using a double-imprinting process for the preconcentration of Pb2+ ions. Journal of Colloid and Interface Science, 450, 254–263. https://doi.org/10.1016/j.jcis.2015.02.074