Abstract
Magnetic composite was synthesized by hydrazine hydrate reduction of cobalt ions on covalent triazine frameworks (CTFs). The CTFs/Co composites are chemically stable in organic solvents; the porous structure and magnetic property contribute to fast adsorption/desorption dynamics, phase separation and high extraction efficiency (52–67%) for interest pyrethroids. Accordingly, CTFs/Co composites were employed for the extraction and pre-concentration of five pyrethroids (bifenthrin, fenpropathrin, cypermethrin, permethrin and fenvalerate) from food samples, followed by gas chromatography (GC)-flame ionization detector (FID) measurement. Under the optimized conditions, the limits of detection for interest pyrethroids were 0.34–0.84 μg/L, with the enrichment factor of 156–201. The developed method was validated by analyzing quality control samples (apple juice, CFAPA-QC198A-1), fruit juice, honey and vegetables (recovery of 73.0–118% for spiked samples). This method is simple, sensitive, selective, environment friendly, and could be employed for other aromatic compounds analysis in food samples.