UiO-66 with missing cluster defects for high-efficient extraction and enrichment of benzoylurea insecticides.

The creation of defects in crystalline structures can tune metal-organic frameworks (MOFs) properties, such as improving their adsorptive and catalytic performance with producing more porosity and active sites. In this work, the bimetallic UiO-66 containing Zn and Zr was prepared. And then UiO-66 with missing cluster defects (UiO-66-1/3) were obtained by acid washing to remove the Zn nodes. UiO-66-1/3 was used as sorbent of dispersive solid-phase extraction (dSPE) to extract and enrich (BUs). Combination with high-performance liquid chromatography-diode array detector (HPLC-DAD) was developed to detect trace BUs in soil samples. Adsorption equilibrium can be reached in 3 min. The method possesses high enrichment factor (202-325), low detection limit (0.005-0.04 ng·mL), and wide linear range (0.02-200 ng·mL). In addition, the recovery rate of UiO-66-1/3 as an adsorbent was still higher than 95% after reused for 16 times. This work provides a new material for the enrichment and detection of benzoylurea insecticides in the environment.