Centrifugation-assisted solid-phase microextraction using pipette-tips filled with microfibers to determine polycyclic aromatic hydrocarbons in river water

For the first time, polymer microfibers filled in pipette tip format were used to extract polycyclic aromatic hydrocarbons from river water. Centrifugal force was used to push the sample through the sorbent, thereby increasing the speed and throughput of the extraction process. A broad range of almost 30 different microfibrous materials, including various polymers and their coated counterparts, were evaluated to identify the most efficient sorbent. Biodegradable polycaprolactone microfibers provided the best recovery rates (72–127%) with relative standard deviations (RSD) of 2.7–6.4%. The method exhibited linearity from 0.1 to 5 µg L⁻¹ for most analytes (R² > 0.9994), except for dibenzo(a,h)anthracene (R² = 0.9981). Preconcentration factors ranged from 2.9 to 5.1. Intra- and inter-day repeatability tests confirmed stability and reusability of the sorbent for over six consecutive extraction cycles conducted within three experimental days. The high permeability of polycaprolactone microfibers allows for short contact times while maintaining high recoveries. The centrifuge-assisted setup enables the processing of up to 36 samples per run. Our approach provides a practical alternative for extracting hydrophobic analytes from water. The novelty of this study lies in the development of a reusable, centrifugation-driven pipette-tip microextraction approach using biodegradable polycaprolactone microfibers for fast and efficient determination of polycyclic aromatic hydrocarbons in water.