Flower-like Co3O4/C3N5 composite as solid-phase microextraction coating for high-efficiency adsorption and preconcentration of polycyclic aromatic hydrocarbons and polychlorinated biphenyls in water

Sensitive detection of environmental pollutants that are harmful to organisms is of great significance for prevention of related diseases. In this work, a flower-like Co3O4/C3N5 composite as solid-phase microextraction fiber coating was developed for extraction of polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs). The Co3O4/C3N5 composite was derived from the multilayer stacked flower shaped Co(OH)2/C3N5 that synthesized by one-pot solvothermal method. Compared with pure monomer materials, the unique structure was maintained and the surface adsorption sites were fully exposed, thereby the adsorption performances of Co3O4/C3N5 were significantly improved. As a result, the enrichment factors were 3010–5012 for PAHs, and 4499–6180 for PCBs. Under the optimized conditions, the developed method showed wide linear range (0.0005–20 ng mL−1) with good linearity (R2 greater than 0.9912), low detection limits (0.00017–0.061 ng mL−1, S/N = 3) and quantification limits (0.0005–0.2 ng mL−1, S/N = 10) for three PAHs and five PCBs. The RSDs (n = 5) of intraday and interday were 2.28–8.35% and 3.49–9.59%, respectively. The reproducibility between fibers (n = 3) was in the range of 7.84–11.96%. The developed method was successfully applied to real water sample with satisfactory recoveries of 81.07–109.1%. As a simple and robust technique, the proposed method will be an alternative way to the analysis of PAHs and PCBs in real samples.