Ionic liquid-modified UiO-66-NH 2 as sorbent of dispersive solid-phase extraction for rapid adsorption and enrichment of benzoylurea insecticides.

Ionic liquid (IL)-modified UiO-66-NH 2 composite was prepared and used as sorbent of dispersed solid-phase extraction (dSPE) for extracting trace benzoylurea insecticides (BUs) from complex environmental matrices. The IL in framework endowed the prepared material had electropositive characteristics, which can produce interaction with electron rich guest molecules, such as BUs. The high thermal and chemical stability of UiO-66-NH 2 /IL enabled it to be reused for 16 times without significant reduction in adsorption performance. Due to the multiple forces including π-π, hydrogen bonding, and fluorine-fluorine interaction, UiO-66-NH 2 /IL showed good adsorption performance, short adsorption time (20 s) and rapid desorption ability (60 s) for BUs. Under the optimal conditions, the method exhibited wide linear range (0.02-500 ng mL -1 ) with correlation coefficient (R 2 ) not worse than 0.9928, high enrichment factor (252-300), and low detection limit (0.005-0.4 ng mL -1 ). The dispersed solid phase extraction coupling with high-performance liquid chromatography-diode array detector (dSPE-HPLC-DAD) was successfully used to detection of BUs in real environmental samples and satisfactory recoveries were obtained (80.5%±2.4-118%±3.2). The results indicated that UiO-66-NH 2 /IL composite can be a potential sorbent for the preconcentration of trace insecticides in environmental samples.