Triphenylamine-based hypercrosslinked organic polymer as adsorbent for the extraction of phenylurea herbicides

A hypercrosslinked organic polymer material (named as PPTPA) was prepared by a simple one-step self-polycondensation of triphenylamine. A series of characterization experiments, including N₂ adsorption, scanning electron microscopy, X-ray diffraction, Fourier transform infrared spectra, and thermogravimetric analysis, were carried out to evaluate the morphology, structure and other intrinsic properties of the PPTPA. To investigate its adsorption performance, the PPTPA was used as the solid-phase extraction adsorbent for the extraction of phenylurea herbicides from water, milk and tomato juice samples followed by high-performance liquid chromatographic analysis. Under optimum conditions, good linearity for the analytes was observed in the range of 0.05-40.0ngmL^-1, 0.1-40.0ngmL^-1 and 0.5-40.0ngmL^-1 for water, milk and tomato juice samples, respectively. The established method also showed low limits of detection (S/N=3) in the range of 0.008-0.01ngmL^-1, 0.01-0.03ngmL^-1 and 0.05-0.1ngmL^-1 for water, milk and tomato juice samples, respectively. The possible adsorption mechanism of the PPTPA towards the analytes was investigated, and the results demonstrated that the hydrogen bonding was the main interaction force between the PPTPA and the analytes. It suggests that the PPTPA can serve as a promisingadsorbent for the efficient pre-enrichment of organic compounds with more hydrogen-bonding donor sites.