Facile synthesis of covalent organic frameworks functionalized with graphene hydrogel for effectively extracting organophosphorus pesticides from vegetables

A novel covalent organic framework material (3DGA@COFs), for use as a solid-phase dispersion sorbent, has been synthesized for extracting organophosphorus pesticides (OPs) from vegetables. The prepared 3DGA@COFs material exhibited many advantageous features, including a large specific surface area (127.95 m(2)/g) and high pore volume (0.0344 cm(3)/g), which made it an ideal sorbent for sample pretreatment. The experimental conditions affecting extraction performance (adsorbent type, adsorbent amount, reaction time, pH, ionic concentration, and eluent) were optimized systematically. The extracted analytes were detected by HPLC-MS/MS. Under optimized conditions, the proposed method exhibited a wide linear range (0.5-100 mu g/L) and low limits of detection (0.01-0.14 mu g/L). The recoveries (75.40%-102.13%) satisfied the requirements for a precise detection method. The proposed method was successfully used for determining malathion, triazophos, quinalphos in lettuce, tomato and cucumber samples, thus indicating the potential of using 3DGA@COFs materials for pretreating vegetable samples.

Automated summary

A novel covalent organic framework material (3DGA@COFs) was synthesized as a solid-phase dispersion sorbent for extracting organophosphorus pesticides (OPs) from vegetables. The material exhibited a large specific surface area and high pore volume, making it an ideal sorbent for sample pretreatment. The proposed method, optimized for various experimental conditions, showed wide linear range, low limits of detection, and satisfactory recoveries for precise detection of OPs in vegetable samples.