Fatty Acids Analysis in Dairy Products via GC-FID Methodology: Leveraging PS/SNW-1 Nanofibers for Enhanced PT-µSPE

In an effort for rapid and simultaneous determination of multiple fatty acids in dairy products, a newly developed sorbent based on polystyrene/Schiff base network-1 (PS/SNW-1) electrospun nanofibers were used for pipette tip-micro solid phase extraction (PT-µSPE) with gas chromatography-flame ionization detector (GC-FID). The porous and hydrophobic nature of PS, in the presence of the SNW-1 as a covalent-organic framework with robust resistance in aqueous and acidic solutions, acceptable thermal stability, a substantial surface area, and an accumulated π-electron system, offers a sorbent with exceptional extraction efficiency. This innovative approach overcomes the limitations encountered when utilizing SNW-1 and PS individually, such as back pressure, leakage, and limited reusability.Under optimum conditions, an outstanding linear dynamic range was obtained in the range of 0.3–30000 µg L⁻¹ for myristic acid, 0.3–45000 µg L⁻¹ for palmitic acid, and 6.0–60000 µg L⁻¹ for stearic acid and oleic acid. Additionally, the method demonstrated a low limit of detection (LOD ≤ 1.8 µg L⁻¹) and limit of quantification (LOQ ≤ 6.0 µg L⁻¹), along with relative standard deviations within the range of 1.19–5.59 % for within-day and 2.83–5.93 % for between-day analyses. Furthermore, satisfactory relative recovery and sorbent reusability were also achieved.