A Dual Approach Combining Metal‐Organic Frameworks and Commercial Solid‐Phase Microextraction Coatings for Monitoring Volatiles in Passion Fruit

ABSTRACT

This study presents the applicability of a solid‐phase microextraction (SPME) coating based on the CIM‐80( Al ) metal‐organic framework (MOF), prepared by in situ solvothermal growth onto braided silver wires, for the untargeted analysis of passion fruit juices. After the characterization of the MOF‐coated fiber by Fourier‐transform infrared spectroscopy, scanning electron microscopy, and powder X‐ray diffraction, it was applied in both headspace (HS)‐ and direct immersion (DI)‐ SPME in combination with gas chromatography‐mass spectrometry. The studies were carried out in comparison with three commercial SPME fibers. Considering all the fibers studied, up to 52 and 26 compounds were tentatively identified via HS‐ and DI‐SPME, respectively. Besides, all fibers presented adequate reproducibility and similar lifetime, even in the DI mode and despite the sample complexity. In HS‐SPME, a total of 25 compounds were tentatively identified with the MOF‐coated fiber. From these analytes, 10 compounds (∼42%) were exclusively detected with the MOF‐coated fiber. In DI‐SPME, 10 compounds were tentatively identified with the MOF‐coated fiber, and four of these compounds (∼50%) were exclusively detected with this fiber. Overall, the results indicate that the MOF‐coated fiber offers a superior selectivity for heavier, less volatile, and less polar analytes, therefore acting as a complementary tool for commercial coatings when intending metabolomic studies for food analysis. The dual approach with MOF‐coated fiber and commercial SPME coatings provides more comprehensive information for food analysis.