Assessment of SPME lab-made microfibers for monitoring the presence of phthalate contaminants in honey sample

The contamination with plastics (nano and micro) is a problem of great concern. In the case of food, the presence of plastics is ascribed to their use as packaging materials which can migrate into different foodstuffs. A need for more efficient and accessible detection techniques becomes a great challenge. In this context, Solid-Phase Microextraction (SPME) emerges as a highly efficient tool to assess the determination of analytes, including microplastics, in different kinds of matrix comprising foods. In this contribution, the design of SPME microfibers is proposed to assess the more efficient detection of phthalates, as model of microplastics, in a sample of honey. SPME microfibers were fabricated using vitreous materials and coated with polyethylene glycol (PEG). The characterization of coated microfibers was performed by FTIR SEM, and TGA. The achieved data confirmed that PEG deposited on the fiber, reached a maximum of 13% respect to the total coated fiber mass. The performance of developed fibers was evaluated using Gas Chromatography coupled with a Mass Spectrometer detector. The results revealed a better separation between the retention times (r.t) of each phthalate when the lab made fibers were employed. In the this case r.t of 23, 33 and 41 min were roughly achieved for detecting diethyl phthalate (DEP), dibutyl phthalate (DBP) and bis(2-ethylhexyl) phthalate (DEHP), respectively. As a difference, when the commercial fiber was used the retention times were narrower distributed reaching r.t of 30, 33, and 39 min for DEP, DBP and DEHP, respectively in the same honey’s sample.