Covalent organic framework-based solid-phase microextraction coupled with electrospray ionization mass spectrometry for in vivo determination of furanocoumarins in citrus fruits.

Furanocoumarins (FCMs) are a group of organic compounds abundantly found in citrus fruits. Excessive intake is closely associated with increased incidence of skin cancer. Consequently, the development of an efficient approach for in vivo determination of FCMs in citrus fruits is of critical importance. In this study, 1,3,5-tris (4-aminophenyl) benzene (TAPB) and 2,4-dihydroxybenzene-1,3,5-tricarbaldehyde (DHTA) were used to synthesize covalent organic framework (COF) as a solid phase microextraction (SPME) probe. The probe showed highly ordered porosity (1.49 nm), outstanding stability, and hydrophobicity. With respect to these superiorities, it was coupled with electrospray ionization mass spectrometry (ESI/MS) to achieve the detection of six FCMs with high enrichment factors (71.3-108.5), and low detection limits (0.003-0.160 μg L-1). The platform was used with great success for the in vivo analysis of FCMs in four citrus fruits, indicating that this platform had good prospects as a powerful instrument for in vivo monitoring fruits.