Preparation of new ion-selective cross-linked poly(vinylimidazole-co-ethylene glycol dimethacrylate) using a double-imprinting process for the preconcentration of Pb2+ ions

摘要

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 42.04 mg Ph2+ 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 40.0 mg of the double-imprinted polymer packed in a minicolumn at 5.0 mL min(-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 0.0-300.0 mu g L-1 (r = 0.999) and a limit of detection of 2.46 mu g L-1 was obtained. The preconcentration factor was found to be 21, the consumptive index 0.95 mL and the concentration efficiency 5.25 min(-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%). (C) 2015 Elsevier Inc. All rights reserved.