Comparison of biodegradable polycaprolactone nanofibers and synthetic polyamide nanofibers as a novel, sustainable sorbent for a spin filter microextraction of xenobiotics from river water

We evaluated the application of nanofibers made from different biodegradable and synthetic polymers as sorbents in a new technique of spin filter fiber-microextraction. Biodegradable polycaprolactone fibers, produced via the meltblowing process exhibited robust hydrophobic interactions with lipophilic analytes and were the most effective. The highly porous and permeable structure of the fibrous material ensured exhaustive extraction of xenobiotics from river water. Recovery rates ranged from 81.8 to 105.2 %, except for 4-nitrophenol, a more polar analyte, for which the recovery was 60 %. Only 10 s were needed for activation, extraction, and elution, significantly reducing the time required to complete the procedure in only 30 s per sample. Our method exhibited excellent analytical performance, achieving linearity in the range of 50–2000 µg L⁻¹ for most analytes (100–2000 µg L⁻¹ for PNP and 2-CP; and 100–1000 µg L⁻¹ for PER) with a coefficient of determination (R²) greater than 0.9952. The limits of detection were recalculated based on the slope of the calibration curves and the standard deviation of six replicate measurements at the lowest calibration point for each analyte, yielding values in the range of 7.0–36.6 µgL^-1. Repeatability between extractions (i.e. inter-extraction precision) was evaluated by performing six parallel runs using different cartridges (n = 6). The obtained RSD precision values ranged from 2.2 to 3.3 % demonstrating the excellent uniformity of the nanofibrous materials filled in the devices . We also assessed the reusability of the individual cartridges by performing six consecutive extractions on the same spin filter (i.e. intra-cartridge precision, n = 6), yielding RSD values between 1.1 and 3.6 %. These results confirm that the spin filters cartridges filled with polycaprolactone nanofibers can be effectively reused for multiple extractions in absence of sample carry-over effect.