A fiber-packed needle-type extraction device with ionic liquid-based molecularly imprinted polymer as coating for extraction of chlorobenzenes in water samples

Abstract

A needle-type extraction device (NTED) packed with ionic liquid-based molecularly imprinted polymers (MIP) coated copper fiber was produced for extraction of chlorobenzenes (CBs) in the aqueous environment followed by detection with GC-FID. Precipitation polymerization was performed to synthesize CBs imprinted polymers (CBs-MIP) with CBs as a mixed template, and 1-vinyl-3-aminoformylmethyl imidazolium chloride ionic liquid ([VAFMIM]Cl) as a functional monomer. Then CBs-MIP was coated on the braided copper fiber surface by sol–gel technology, which was served as a coated fiber to extract five trace CBs in drinking water, river water and industrial wastewater. The effects of several experimental conditions on extraction, including extraction time and temperature, pump flow rate, stirring speed, desorption time and temperature were studied by the single factor and experimental design method. A Plackett-Burman design (PBD) was used to screen the significant factors and a Box-Behnken design (BBD) was applied to optimize the significant variables to obtain the optimum extraction conditions. The limits of detection (0.0073–0.0130 μg L−1) and enrichment factors (2158–4087) for studied CBs were obtained after optimization. Moreover, the recoveries of CBs spiked in real water samples were 80.01–97.10% with RSD less than 7.70%. The experimental results confirmed that the NTED packed with CBs-MIP coated fiber is a promising device for extracting trace CBs from the water matrix.