Porous thin-film molecularly imprinted polymer device for simultaneous determination of phenol, alkylphenol and chlorophenol compounds in water

Abstract

A porous water-compatible molecularly imprinted polymer (MIP) coating using catechol as a pseudo-template and a water-soluble functional monomer (4-vinyl benzoic acid) with ethylene glycol dimethacrylate as the crosslinker was developed for extraction of phenols from environmental water samples. The MIP devices were combined with ultra high performance liquid chromatography with a photodiode array detector (UHPLC-PDA) suitable for the simultaneous determination of trace levels of phenolic compounds with a wide range of polarities —phenol, alkylphenols and chlorophenols— in seawater and produced water. Parameters that influence extraction efficiency (salinity, pH, polymer mass, desorption solvent, and desorption time) were optimized to give method detection limits (LOD) ranging from 0.1 to 2 μg L−1 and linearity (R2>0.99) over at least three orders of magnitude for the hydrophobic phenols (e.g., 0.5–1000 μg L−1 for 2,4,6-trichlorophenol) and ~2 orders of magnitude for the light phenols (e.g., 10–120 μg L−1 for phenol, 5–120 μg L−1 for methylphenols and 2-chlorophenol, 0.5–120 μg L−1 3-methyl-4-chlorophenol and 2,4-dichlorophenol). The recoveries from authentic spiked samples ranged from 85 to 100% with %RSDs of 0.2–14% for seawater and 81–107% with %RSD of 0.1–11% for produced water. The resulting MIP-based extraction requires no pre-conditioning of the sorbent, and because the required sample size is small and sample manipulation is limited, the method is easy to multiplex for high throughput sample processing.