Development of a novel Polyacrylonitrile/ metal-organicframework-199 electrospunnanofiber adsorbent for thin film microextraction of Heptachlor and Endosulfan in vegetables and fruits samples

In this work, electrospun polyacrylonitrile/metal-organic frameworks-199 (PAN/MOF-199) nanofiber film was synthesized and investigated as a novel adsorbent for thin film microextraction (TFME) of heptachlor and endosulfan in vegetables and fruits samples. Some properties of the prepared PAN/MOF- 199 nanofiber film, including morphology, structure, wettability, solvent stability and extraction performance were studied systematically. Porous fibrous structure, large surface area, good stability, strong hydrophobicity and excellent extraction efficiency were obtained for the film. Based on the PAN/MOF-199 film, a thin film microextraction-gas chromatography-flamionization (TFME-GC-FID) method was developed, and the experimental parameters that affected the extraction and desorption were optimized. Under the optimal conditions, the limits of detection (LODs) were in the range of 0.02- 17.3 μL-1 for the analysis of six aldehydes. Good linearity was achieved with correlation coefficients (R2) being lager than 0.9943. Satisfactory recovery (92 % to 112%) and acceptable reproducibility (relative standard deviation: 2.1 % to 4.3%) were also obtained for the method. The developed TFME-GC-FID method has been successfully applied to the analysis of heptachlor and endosulfanin the in vegetables and fruits samples of lung cancer patients and healthy people.The method possesses the advantages of simplicity, rapidity, cost-effective, sensitivity and non-invasion, it provides an alternative tool for the determination of heptachlor and endosulfan in vegetables and fruits.