Carbon fibers coated with covalent organic framework for online in-tube solid-phase microextraction of tetrabromobisphenol A derivatives in water

Tetrabromobisphenol A (TBBPA) derivatives as new pollutants attracted more and more attention. Due to the trace level of TBBPA derivatives or the complex sample matrix, sample pretreatment was often required for sensitive determination. However, sample pretreatment methods including solid-phase extraction, liquid extraction, and fiber solid-phase microextraction were complicated procedures, inefficient, and offline operation with detection techniques. A coating of covalent organic framework (COF) was grown onto carbon fibers (CFs) via a Schiff-based reaction at room temperature. The COF-coated CFs (COF-CFs) were filled into one tube for enriching TBBPA derivatives in water by in-tube solid-phase microextraction (IT-SPME). After the optimization of extraction and desorption factors, online IT-SPME-HPLC-DAD method was developed. The method exhibited a wide linear range (0.167–10.0 µg L⁻¹, 0.33–10.0 µg L⁻¹), and a low detection limit (0.05 µg L⁻¹) resulting from high enrichment factors (936–2187) within 20.0 min. The method was applied in the detection of TBBPA derivatives in water samples, demonstrating good practical applicability. Compared with other analytical methods, the method was simple, efficient, and online operation. The extraction material is expected to capture other pollutants in environmental, food, biological and other fields.