Determination of abamectin in food based on magnetic covalent organic frameworks and HPLC-FLD

Abamectin is widely applied in agriculture and aquaculture, easily accumulates through the food chain and endangers human health. Sample pretreatment is the crucial and fundamental procedure prior to the precise analysis of trace abamectin. Herein, 4,4',4''-(1,3,5-triazine-2,4,6-triyl) trianiline (Tz) and 2,5-dihydroxy-1,4-benzenedicarboxaldehyde (Da) were modified on the surface of Fe3O4 nanoparticles to prepare magnetic covalent organic frameworks (Fe3O4@TzDa) adsorbent for abamectin. Depending on the large specific surface of TzDa and hydrogen bonding, π-π and hydrophobic interactions between TzDa and abamectin, the efficient magnetic solid-phase extraction (MSPE) of abamectin residue was achieved. Under the optimal MSPE conditions, the developed MSPE-HPLC-FLD based on Fe3O4@TzDa method for abamectin residue afforded good linearity (0.05-500μgL-1) with high R2 (0.998) and low limit of detection (0.015μgL-1). The developed MSPE-HPLC method was evaluated and successfully applied to determine abamectin residue in lake water, milk and peach juice samples with satisfactory recoveries (87.1-119.1%) and relative standard deviations (1.9-4.9%).