Efficient extraction of perfluorocarboxylic acids in complex samples with a monolithic adsorbent combining fluorophilic and anion-exchange interactions.

Efficient extraction of perfluorocarboxylic acids (PFCAs) is a key step for the accurate and sensitive determination of PFCAs due to their low concentration and the complexity of sample matrices. Herein, according to the chemical characteristics of PFCAs, a new adsorbent based on poly (2,2,3,3,4,4,5,5,6,6,7,7-dodecafluoroheptyl acrylate/(vinylbenzyl)trimethylammonium chloride-co-divinylbenzene/ethylenedimethacrylate) monolith was fabricated and utilized as the extraction medium of multiple monolithic fiber solid-phase microextraction (MMF-SPME). Results well indicted that the prepared monolithic adsorbent (MA) could efficient extract PFCAs through fluorophilic and anion-exchange interactions. Under the optimal conditions, the MA/MMF-SPME was combined with HPLC-MS/MS for the sensitive monitoring of ultra-trace PFCAs in water and milks samples. The limits of detection (S/N = 3) of the target PFCAs in water and milk samples were 0.40-4.40 ng/L and 0.9-12.1 ng/L, respectively. Furthermore, the proposed method also exhibited some merits including wide linear dynamic ranges, satisfactory sensitivity, good method precision and low consumption of sample and organic solvent. Isotope internal standard calibration curve method was used to quantify the concentration of PFCAs in real samples, and trace levels of PFCAs in tap water and milk samples had been successfully detected.