Preparation of an efficient magnetic nano-sorbent based on modified cellulose and carboxylated carbon nano-tubes for extraction of pesticides from food and agricultural water samples before GC-FID analysis

This paper reports the direct synthesis approach of carboxamide functionalized magnetic nano-composite named Fe3O4@SiO2-NH2@dialdehyde cellulose (DAC)@CNT-COOH as an effectual sorbent for the co-extraction of seven agricultural insecticides and herbicides from vegetable, fruit, and water samples using the magnetic dispersive micro-solid-phase extraction procedure. Under the optimized extraction conditions (sorbent amount: 18.1 mg; desorption time: 6.5 min; desorption solvent volume: 185 μL; desorption solvent: acetonitrile; extraction time: 9.5 min; pH of sample solution: 7.0, and salt content: 5.0 % w/v sodium chloride), good linearity within the range 0.5-1200 ng/mL (R2 ≥ 0.998) was achieved. Extraction efficiencies were in the range 63.4-84.1 %, the limits of detection were 0.08-1.0 ng/mL, and acceptable relative recoveries (87.6-103.8 %), and precisions were also achieved (RSDs < 6.8 %, n = 3). Ultimately, the obtained results showed that the developed method could be applied to determine trace amounts of desired analytes in various agricultural water and food samples.