Poly(calixarene ionic liquid) modified Fe3O4 nanoparticles as new sorbent for extraction of flavonoids in fruit juice and green tea

A novel magnetic sorbent has been synthesized by co-polymerization of calixarene ionic liquid and mercaptan-modified Fe3O4 particles. This material was used as a sorbent for dispersive solid phase extraction of trace-level flavonoids in the samples of bottled fruit juice and green tea without other pre-treatments. The experimental parameters were investigated and optimized. Coupled with high performance liquid chromatography, an analytical method was established and successfully applied to the determination of flavonoids in these beverages. The proposed method showed good linearity for the analytes with a correlation coefficient (r) > 0.9982, and detection limits for the flavonoids ranged 0.15-0.75 ng mL−1 were achieved. The proposed method has been used successfully to determine flavonoids in bottled fruit juice and green tea samples with satisfactory recoveries of 92.5-104.8% and relative standard deviations ≤ 5.2%. The results suggest that poly(calixarene ionic liquid) modified Fe3O4 nanoparticles can be used in the extraction of flavonoids in beverage samples.