• Stable and inexpensive carbon fibers displayed great potential for in-tube SPME. • Carbon fibers enriched PAHs by hydrophobic and π-stacking effects. • An online IT-SPME-HPLC-DAD method sensitively detected PAHs in seawater. • Carbon fibers are also promising for the enrichment or adsorption of other targets. Due to the carcinogenic toxicity of polycyclic aromatic hydrocarbons (PAHs), it is necessary to sensitively detect PAHs in seawater. Given their trace levels in seawater, sample pretreatment was required before the detection. In this work, carbon fibers (CFs) of 57 mg were filled into 30.0 cm length of polyetheretherketone tube for in-tube solid-phase microextraction (IT-SPME). The morphology of CFs displayed the grooved surface and micrometer diameters (8–10 μm). The tube was adopted to enrich PAHs, then the optimum extraction and desorption factors (sample volume of 60 mL, flow rate of 2.0 mL min −1 , and desorption time of 2.0 min) were achieved by coupling with liquid chromatographic detection. Furthermore, online IT-SPME-HPLC-DAD method was established for PAHs in seawater, giving linear ranges (0.033–10.0 μg L −1 , 0.167–10.0 μg L −1 ), and low detection limits (0.01–0.05 μg L −1 ) resulting from high enriching effect (100–860) within 18.0 min. Then, the method was successfully applied in the detection of PAHs in seawater samples. Compared with other analytical methods, the method was online, simple and efficient. In the future, the CFs-based method is expected to determine other targets from environmental, food, biological and other fields.
Sun et al. (Sun,) studied this question.