Preparation of an imprinted monolith for field simultaneously selective separation and enrichment of nitrophenols and lead (II) ion in water samples

Abstract

Imprinted materials have gained significant attention due to its highly specific recognition performance. However, there is no study that using molecule and ion as mixed templates to prepare hybrid imprinted material for simultaneously selective separation and enrichment of molecules and ion. Here, a new strategy employing organic molecule and heavy metal ion as mixed templates to prepare imprinted material was proposed. 2,4-Dinitrophenol (2,4-DNP) and Pb2+ were selected as model templates to in-situ synthesize adsorbent based on imprinted monolith (AIM) in pipette tip. The obtained AIMs were used as the extraction medium of home-made multiple channels in-tip microextraction device (MCMD) for field simultaneously selective entrapment of nitrophenols (NPs) and Pb2+. The selection of functional monomers was well verified with Density function theory. Under the optimal fabrication conditions, the AIM displayed high specific recognition capability towards 2,4-DNP and Pb2+ with imprinted factors 7.31 and 5.20, respectively, and corresponding adsorption capacities were as high as 27.8 mg/g and 20.3 mg/g, respectively. The practicality of proposed AIM/MCMD was evaluated by simultaneously on-site selective capture of NPs and Pb2+ in various environmental waters prior to quantification with HPLC (for NPs) and atomic absorption spectrometry (for Pb2+). Results well evidence that the proposed strategy is feasible in the preparation of imprinted polymer for simultaneously specific extraction of molecules and metal ion, and the developed AIM/MCMD is a useful field sample preparation method for reliable quantification of NPs and Pb2+ in aqueous samples.