Facile synthesis of spherical covalent organic frameworks for enrichment and quantification of aryl organophosphate esters in mouse serum and tissues

Here, an imine‐linked‐based spherical covalent organic framework (COF) was prepared at room temperature. The as‐synthesized spherical COF served as an adsorbent in dispersive solid‐phase extraction (dSPE), by its virtue of great surface area (1542.68 m 2 /g), regular distribution of pore size (2.95 nm), and excellent stability. Therefore, a simple and high‐efficiency dispersive solid phase extraction method based on a spherical COF coupled with high‐performance liquid chromatography‐tandem mass spectrometry (HPLC‐MS/MS) was established to determine aryl organophosphate esters in biological samples. This approach displayed favorable linearity in the range of 10.0–1000.0 ng/L (r > 0.9989), a high signal enhancement factor (58.8–181.8 folds) with low limits of detection (0.3–3.3 ng/L). Moreover, it could effectively eliminate complex matrix interference to accurately extract seven aryl organophosphate esters from mouse serum and tissue samples with spiked recoveries of 82.0%–117.4%. The as‐synthesized spherical COF has been successfully applied in sample preparation. The dSPE‐HPLC‐MS/MS method based on a spherical COF has potential application to study the pollutants' metabolism in vivo.