Dummy-surface molecularly imprinted polymers based on magnetic graphene oxide for selective extraction and quantification of pyrethroids pesticides in fruit juices

A highly binding dummy template molecularly imprinted polymers (Fe 3 O 4 -NH 2 @GO@MIPs) was synthesized used Fe 3 O 4 -NH 2 @GO as carrier by dummy surface molecular imprinting technique (DSMIT) for the first time. Fe 3 O 4 -NH 2 @GO@MIPs were characterized by fourier transform infrared (FT-IR), scanning electron microscope (SEM), transmission electron microscope (TEM), thermogravimetric analysis (TGA), brunauer emmett teller (BET) and vibrating specimen magnetometer (VSM). Adsorption and selectivity experiments of Fe 3 O 4 -NH 2 @GO@MIPs and non-imprinted polymers (Fe 3 O 4 -NH 2 @GO@NIPs) verified that the Fe 3 O 4 -NH 2 @GO@MIPs had a better selectivity and adsorption properties for five pyrethroids pesticides. Adsorption test results revealed that the adsorption behaviors of pyrethroids onto Fe 3 O 4 -NH 2 @GO@MIPs followed Langmuir equation adsorption isotherm and pseudo-second-order kinetic models. Fe 3 O 4 -NH 2 @GO@MIPs were used as sorbent in magnetic solid phase extraction (MSPE) to extract five pyrethroids from fruit juice samples, following desorption with acidified ethyl acetate, the pyrethroids were quantified by gas chromatography with electron capture detection (GC-ECD). The developed method MSPE coupled with GC-ECD achieved satisfactory recovery (72.1–106.8%) with RSD less than 10.8%, and the detection limits (LOD) for fenpropathrin (FENP), lambda-cyhalothrin (LC), cyfluthrin (CYF), fenvalerate (FEN) and deltamethrin (DEL) ranged from 0.007 to 0.015 μg/L. Compared to other methods, the procedure MSPE-GC-ECD based on Fe 3 O 4 -NH 2 @GO@MIPs in this work demonstrated to be a more convenient and practical method for the separation, enrichment, and detection of pyrethroids pesticides from fruit juice samples.