A practical interface designed for on-line polymer monolith microextraction: Synthesis and application of poly(4-vinylpyridine-co-ethylene glycol dimethacrylate) monolith

A simple and facile needle-adapter was designed for constructing manual on-line polymer monolith microextraction-high performance liquid chromatography (PMME-HPLC). A capillary poly(4-vinylpyridine-co-ethylene glycol dimethacrylate) [poly(VP-co-EGDMA)] monolith was prepared by in situ polymerization, using 4-vinylpyridine (VP) and ethylene glycol dimethacrylate (EGDMA) as functional monomer and cross-linker, respectively. The synthesized monolith was used as the extraction medium for concentrating four EPA priority pollutants, 2-chlorophenol, 2,4-dichlorophenol, 2,4,6-trichlorophenol and pentachlorophenol, from water samples. The effect of the dosage of porogen polyethylene glycol 6000 (PEG) on back pressure and extraction performance of the capillary monolith was also investigated. Moreover, the influences of several parameters (such as extraction time, desorption time, content of MeOH in sample solution and sample pH) were examined to obtain the optimal PMME conditions. As a result, the established on-line PMME-HPLC protocol, with good extraction efficiency (80.6–91.7%), satisfactory recovery (94.7–106% and 76.8–86.3% for water and serum samples, respectively) and low detection limit (0.3–1.4 μg/L), exhibited potential applicability for the analysis of chlorophenols in environmental and biological samples.

► Manual on-line PMME-HPLC system was constructed based on a facile needle-adapter.
► Poly(VP-co-EGDMA) monolith was prepared as a new PMME medium.
► The PMME-HPLC system can be used to extract and determine chlorophenols.
► Less sample consumption and shorter extraction time were needed for water and serum.
► Generally lower LODs relative to other off-line SPME-HPLC methods was another advantage.