High efficient solid-phase microextraction based on a covalent organic framework for determination of trifluralin and chlorpyrifos in water and food samples by GC-CD-IMS.

Novel porous covalent organic framework (COF) based on condensation reaction between cyanuric chloride, 4,4'-ethylendianiline, and 3,4,9,10-perylenetetracarboxylic dianhydride was synthesized via sealed tube condition. The results COF was used as a new adsorbent for solid-phase microextraction (SPME) for extracting trifluralin and chlorpyrifos from vegetables, fruit samples, and wastewater. Gas chromatograph with a corona discharge-ion mobility spectrometer as the detector was also used for analyzing the target analytes. Some parameters that affected the extraction, such as stirring rate, time and temperature of extraction and pH were investigated, exhaustively. The detection limits were 0.13, and 0.15 µg/L and the linear ranges of 0.45-20 and 0.50-25 µg/L with a linearity coefficient of 0.9965 and 0.9987 were also obtained for trifluralin and chlorpyrifos, respectively. The method was applied successfully to analyze some real samples of cucumber, carrot, grape, and agriculture wastewater, and the results showed a relative recovery in the range of 87% to 110%.