Ti4+ modified melamine foam in the pipette tip for effective solid-phase extraction of glyphosate in aqueous samples

Glyphosate, a widely used herbicide, is prone to residue in the environment that may cause harm to humans. In this work, titanium ion-modified melamine foams (MF/PDA/Ti4+) were prepared as sorbents to achieve rapid extraction of glyphosate by pipette-tip solid-phase extraction (PTSPE). The MF/PDA/Ti4+ was characterized by SEM, EDS, XPS, and TGA, and its adsorption properties were evaluated by adsorption kinetics and isotherm experiments. The porous structure and good mechanical properties of MF made the MF/PDA/Ti4+ fill into the pipette-tip easily and could achieve low back pressure. The developed PTSPE method showcased short extraction time (<2 min) for glyphosate and the limits of detection (LOD, 3σ/k) was 4.9 μg/L. It was applied in aqueous samples (tap water, lake water, tea drink, and orange juice) with recoveries ranging from 82.8 % to 108.2 % and the relative standard deviation (RSD, n = 3) was less than 7.7 %, demonstrating broad perspectives on the extraction of glyphosate from the aquatic and terrestrial environment.