Covalent organic framework-based solid phase microextraction coupled with electrospray ionization mass spectrometry for the quantitative assessment of abnormal bile acids by triclosan exposure in mice

Bile acids, a representative diagnostic indicator of liver function, are used to visualize the extent of liver injury. Numerous studies have shown that triclosan (TCS) exposure leads to abnormal bile acid metabolism. As a result, there is a requirement to develop a fast and smart means to quantitatively monitor abnormal bile acids from exposure to triclosan in bio-sample. In this work, solid-phase microextraction (SPME) probes of sea urchin-like covalent organic frameworks (COF) were in situ synthesized on steel needles by using 1,3,5-tris(4-aminophenyl)benzene (TAPB) and 2,5-dimethoxybenzene-1,4-dicarboxaldehyde (DMTP) as two organic units and employed for extraction of bile acids. This TAPB-DMTP-COF-SPME possessed an excellent specified surface area (3351 m² g⁻¹) and a high regular porosity (∼3.6 nm), which was an ideal adsorbent to concentrate bile acids efficiently. The created probe, together with electrospray ionization mass spectrometry (ESI/MS), proved to be a fast and specific assay for the detection of bile acids in bio-samples. The proposed method had a low limitation of detection (0.03 μg L⁻¹), good linearity (R² ≥ 0.9931), wide linear range (0.10–1000.00 μg L⁻¹) and excellent enrichment factor (63.60–252.00). Based on these excellent properties, it was successful application for the analyzing of bile acids in mice liver and feces, demonstrating the great potential of TAPB-DMTP-COF-SPME-ESI/MS in bile acids detection and liver injury diagnosis.