Monitoring residue levels of multiple types pesticides in chrysanthemum (Chrysanthemum morifolium Ramat) and its residue pattern in diet consumption

In this study, a modified preparation method named "Quick, Easy, Cheap, Effective, Rugged and Safe" (QuEChERS) was designed to detect six pesticide residues (fenthion, pendimethalin, trifloxystrobin, bifenazate, pyridaben, and pyraclostrobin) in 25 chrysanthemum (Chrysanthemum morifolium Ramat) samples by the gas chromatography-mass spectrometry (GC-MS) analysis. Prior to GC-MS analysis, extraction was performed using acetonitrile-2.5 % formic acid with European standard (EN) QuEChERS method extraction salts, and the matrix was purified with a combination of sorbent primary secondary amine/graphitized carbon black/octadecylsilane (PSA/GCB/C18). The limits of detection and quantification were then measured by applying matrix-matched calibration curves (R2 ≥ 0.999) in the ranges of 0.35–3.25 and 1.04–9.76 μg·kg−1, respectively. By quantitative analysis, the recoveries of pesticides ranged from 80.14 % to 98.57 % with the relative standard deviations