Construction of novel hyper-crosslinked polymers with adjustable hydrophilicity for efficient extraction of nitroimidazoles.

To effectively control food safety risks caused by nitroimidazoles (NDZs), a sensitive detection method was established on the basis of a newly-developed solid-phase extraction (SPE) sorbent named as Phl-TBM that is a porous polymer prepared by crosslinking natural phloretin with (2,4,6-tris(bromomethyl)mesitylene. The Phl-TBM presented outstanding NDZs adsorption capacity, which can be ascribed to its well-developed porosity and multiple hydrogen bonding sites. With Phl-TBM as SPE sorbent, NDZs were successfully isolated and enriched from lake water, Basa fish, and beef before being assayed by high-performance liquid chromatography-diode array detector. This Phl-TBM based method has a detection limit of 0.02-0.06 ng mL in lake water, 0.60-1.50 ng g in Basa fish, and 0.70-1.20 ng g in beef. The method recoveries are 80.0-120 % with relative standard deviations less than 8.1 %. This study presents an effective and feasible approach for detection of NDZs residues at trace level.