Hydroxylated magnetic microporous organic network for efficient magnetic solid phase extraction of trace triazine herbicides

Abstract

Here we covalently constructed abundant long-chain hydroxyl groups-functionalized magnetic microporous organic networks (MMON-2OH) for detection of eight Triazine herbicides (THs) in honey and water samples. MMON-2OH owned a high surface area (287.86 m²/g), enhanced water compatibility, and increased exposure of long-chain hydroxyl groups, which significantly improved enrichment capacity for THs. Theoretical analyses and characterization data revealed interaction mechanisms, including hydrogen bonds (N-H···O and O-H···N), halogen bond (Cl···N) and π stackings (NH-π, CH-π and π-π). This approach was developed for the detection of THs, achieving a low detection limit 0.03∼0.6 ng⋅L^-1 for water, and 0.006∼0.134 μg·kg^-1 for honey. Trace concentrations of THs, ranging from 1.0∼21.2 ng⋅L^-1 in surface water and 0.1∼0.9 μg·kg^-1 in honey, were successfully detected. Sample spiked recovery experiments demonstrated recoveries between 72.1-116.2 %, validating accuracy and applicability of method. This study realizes a speedy and sensitive determination of THs, showcasing potential of MMON-2OH in pollutant removal and food safety maintenance.

Keywords: Adsorption mechanism; Honey; Long-chain hydroxyl and triazine-based MON; Magnetic solid−phase extraction; Triazine herbicides.