A fast and simple procedure for the synthesis of a zinc and 1,4-benzene dicarboxylic acid metal-organic framework and its evaluation as a sorbent for dispersive micro solid phase extraction of pesticide residues.

In this work, Zn-1,4-benzenedicarboxylate metal-organic framework was synthesized by a simple hydrothermal process and used in dispersive micro solid phase extraction of some pesticide from various fruit juice and water samples. Seven widely consumed pesticides in agriculture (chlorpyrifos, haloxyfop--methyl, oxadiazon, diniconazole, clodinafop-propargyl, fenpropathrin, and fenaxoprop--ethyl) were selected as target analytes. In this work, dispersive micro solid phase extraction was followed by a liquid phase microextraction method to achieve more enrichment of the analytes, and the enriched analytes were quantified using a gas chromatography-flame ionization detector. The sorbent was authenticated by Fourier transform infrared spectrophotometry, X-ray diffraction, energy dispersive X-ray analysis, and scanning electron microscope imaging. The factors affecting the extraction efficiency of the developed method were investigated, and the validation of the method under the optimized extraction conditions presented satisfactory results for precision and trueness, with limits of detection and quantification in the ranges of 0.50-0.90 and 1.5-2.7 μg L, respectively. Enrichment factors and extraction recoveries were in the ranges of 239-392% and 47-78%, respectively. One river water and some fruit and vegetable juice samples were analyzed by the recommended method, and the obtained recoveries were between 90% and 102%.