Determination of Benzimidazoles in Chicken and Egg Samples by Urea-Based Covalent Organic Polymer (UCOP) Pipette Tip-Solid-Phase Extraction (PT-SPE) and High-Performance Liquid Chromatography-Tandem Mass Spectrometry (HPLC-MS)

A urea-based covalent organic polymer (UCOP), was synthesized using 1,4-phenylene diisocyanate (PPDI) and 4,4 & PRIME;,4 & DPRIME;-(1,3,5-triazine-2,4,6-triyl) trianiline (TTTA) and characterized by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and nitrogen adsorption-desorption isotherm analysis. The prepared material was employed as an adsorbent for pipette tip-solid-phase extraction (PT-SPE) for benzimidazoles before high-performance liquid chromatography-tandem mass spectrometry analysis (HPLC-MS). The parameters affecting the isolation efficiency, including salt concentration, sample pH, mass of adsorbent, and types and volumes of eluent, were optimized. Using these conditions, PT-SPE provided good linearity from 0.1 to 10 & mu;g kg(-1) with low limits of detections (LODs) of 0.02 & mu;g kg(-1) together with good precision (relative standard deviations from 4.2 to 8.3%) and accuracy (recoveries from 76.2 to 84.8%). The results demonstrate that the urea-based covalent organic polymer has the potential for the enrichment of trace benzimidazoles.