Development of solid-phase microextraction with multiple interactions-based monolithic fibers for the sensitive...

Due to highly fluorinated and di-anionic characters, it is great challenging to enrich perfluoroalkyl phosphonic acids (PFPAs). According to the unique chemical properties and molecular structure of PFPAs, a monolithic adsorbent using dodecafluoroheptyl acrylate and 4-vinylbenzyltrimethylammonium chloride as mixed functional monomers was synthesized and utilized as the extraction medium of multiple monolithic fibers solid-phase microextraction (MMF-SPME). Results well evidenced that the obtained adsorbent could enrich PFPAs effectively by means of multiple interactions including fluorophilic and anion-exchange interactions. Under the optimized synthesized and extraction conditions, a sensitive approach for the monitoring of trace levels of PFPAs in water and vegetable samples was developed by the combination of MMF-SPME and high performance liquid chromatography tandem mass spectrometry (HPLC-MS/MS). Limits of detection (LODs, S/N = 3) for water and vegetable samples were in the ranges of 0.00011-0.00086 μg/L and 0.0022-0.055 μg/kg, respectively. The introduced method was successfully applied to monitor target PFPAs in lake water, wastewater, pumpkin and cucumber samples. Recoveries at different spiking levels and the relative standard deviations for precision were in the ranges of 80.6-120% and 0.9-12%, respectively. Compared to previously reported approaches, the current method displays some merits such as simple operation, satisfactory sensitivity, low cost and eco-friendliness.