Green preparation of magnetic pyrene-based hyper-cross-linked polymer using dual-purpose ferric chloride reagent for extraction of polycyclic aromatic hydrocarbons from natural water bodies

A magnetic hyper-cross-linked polymer Fe 3 O 4 /HCP PYR was prepared using pyrene as the monomer and formaldehyde dimethyl acetal (FDA) as the cross-linking agent. The objective of green chemistry was achieved by employing FeCl 3 during the synthesis, as it played a dual role of a catalyst for the Friedel-Crafts reaction and an iron source for the synthesis of magnetic Fe 3 O 4 , thus maximizing efficiency and minimizing waste. Fe 3 O 4 /HCP PYR was applied as a sorbent for magnetic solid-phase extraction (MSPE) to extract fifteen polycyclic aromatic hydrocarbons (PAHs) from water. The effects of different parameters such as the quantity of adsorbent, the extraction time, the desorption conditions, the pH value and the effect of the salt concentration on the extraction efficiency were optimized. A simple and efficient method in combination with gas chromatography-mass spectrometry (GC–MS) (Fe 3 O 4 /HCP PYR −MSPE/GC–MS) was developed and successfully applied for the detection of PAHs in environmental water samples The analytical method showed LODs in the range of 0.004−0.06 µg L −1 , which proved to be adequate for the detection all 15 PAHs at trace concentration. Spiked recoveries of PAHs in actual water samples ranged from 85.2 % to 118.5 % with relative standard deviations (RSDs) below 10.2%. These results indicate that the method has a good potential for reusability and possesses excellent sensitivity. This study showcased the potential of Fe 3 O 4 /HCP PYR composites in effectively removing organic pollutants from the aqueous environments, demonstrating their ability for water treatment applications.