Exhaustive extraction of pesticides through MOF-801-oriented dispersive micro solid phase extraction coupled with gas-assisted evaporation

In this study, for the first time, metal-organic framework-801 (MOF-801) was applied as an adsorbent for pesticide analysis. The high surface area of the adsorbent (780 m2 g-1) positively affected the extraction efficiency. Also, the first-ever attempt was done to couple an MOF-oriented adsorptive process with evaporation for preconcentration aim. The process was followed by dissolving the residue in a microliter level of an organic solvent. Initially, the particles of MOF-801 were subjected to the solution of interest having dissolved sodium sulfate and vortexed. After centrifugation and discarding the supernatant, acetonitrile was added onto the adsorbent and vortexed. After centrifugation, the acetonitrile phase underwent evaporation using the designed device. After complete evaporation, a microliter level of 1,2-dibromoethane was used to elute the inner perimeter of the conical bottom glass test tube by vortexing. Finally, one microliter of the organic phase was injected into a gas chromatography equipped with a flame ionization detector. Reaching the exhaustive extraction conditions with higher than 90% extraction recoveries, low limits of detection (0.35-2.10 & mu;g L-1) and quantification (1.16-7.00 & mu;g L-1), high enrichment factors (455-490), using bare MOF-801 in analytical method development, nearly no analyte loss during the extraction, and decreasing the applied volume of organic solvent in the process are the main highlights of the research.