Development of an Extraction Method Based on a Zirconium-based Metal Organic Framework for the Detection and Determination of some Pesticides in Juice Samples Using GC-FID

The proposed analytical method tries to illustrate a new approach for the extraction of some pesticides from different fruit beverages (orange, pineapple, cherry, and mango) using UiO-۶۶ as a capable adsorbent. Further preconcentration for heightening enrichment factors of the analytes was accomplished using a dispersive liquid-liquid microextraction. The synthesized adsorbent was carefully characterized using nitrogen adsorption/desorption, X-ray diffraction, MAP, Fourier transform infrared spectrophotometry, energy dispersive X-ray, and scanning electron microscopy analyses. The performed analyses proved the successful formation of the desired compound. After the sorption of the target compounds onto UiO-۶۶ particles by vortexing, the adsorbent was separated by centrifugation. The analyte-loaded adsorbent was treated with ۱.۰ mL of acetonitrile for the aim of desorption. The obtained eluate containing the desorbed pesticides was mixed with ۳۸ µL of ۱,۱,۱-trichloroethane and hastily injected into sodium chloride solution. After the centrifugation, an aliquot of the sedimented phase was injected into a gas chromatograph equipped with a flame ionization detector. Satisfactory figures of merit obtained in this survey consisted of high enrichment factors (۲۱۵-۲۷۵), acceptable extraction recoveries (۴۳-۵۵%), low limits of detection (۱.۱۰-۲.۳۵ µg L-۱) and quantification (۳.۶۶-۷.۸۲ µg L-۱), low relative standard deviations (≤ ۷.۸%), and wide linear ranges. Also, the proposed method benefits from the high surface area of the adsorbent and low matrix effect.

Keywords:

Dispersive liquid-liquid microextraction , Dispersive micro solid phase extraction , Fruit beverage , Pesticide , Sample preparation , UiO-۶۶