Magnetic effervescence tablet-assisted switchable hydrophilicity solvent-based liquid phase microextraction of triazine herbicides in water samples

A method for the determination of triazine herbicides in water samples was established by magnetic effervescence tablet-assisted switchable hydrophilicity solvent-based liquid phase microextraction procedure (META-SHS-LPME) coupled with high-performance liquid chromatography with diode array detection. The magnetic effervescence tablet, composed of citric acid, sodium hexanoate, sodium bicarbonate, and Fe3O4 nanoparticles, combined extractant generation, dispersion, and magnetic recovery into one step. Citric acid could react with sodium hexanoate and sodium bicarbonate to generate hexanoic acid and carbon dioxide in situ, respectively. Carbon dioxide bubbles assisted the eco-friendly extractant hexanoic acid to fully contact with target compounds. Fe3O4 nanopartides containing extractant and triazine herbicides were isolated from the sample solution using an external magnet. Good linearity was achieved in the range of 50-5000 ng mL(-1) with a correlation coefficient greater than 0.997. The limit of detection was within 0.10-0.13 ng mL(-1). The extraction recovery of triazine her- bicides were 81.4-96.7% in well, pond, and river waters. Overall, the proposed method was a simple, efficient, and eco-friendly analytical approach for determining triazine herbicide residues in water samples. (C) 2020 Elsevier B.V. All rights reserved.