Trace determination of triazine herbicides in fruit and vegetables using novel hydrophobic deep eutectic solvent-based dispersive liquid-liquid microextraction followed by high-performance liquid chromatography-ultraviolet.

Abstract

In the present research, a novel hydrophobic deep eutectic solvent-based dispersive liquid-liquid microextraction technique was established and combined with high-performance liquid chromatography-ultraviolet for the determination of triazine herbicides in fruit and vegetable samples. A deep eutectic solvent was synthesized using l-menthol as a hydrogen bond acceptor and ethylene glycol as a hydrogen bond donor and used as a green extractant. The characterization of deep eutectic solvent was investigated by Fourier-transform infrared, nuclear magnetic resonance, and thermogravimetric analysis. Under the optimum conditions, relative standard deviation values for intra-day and inter-day of the method based on seven replicate measurements of 50.0μg/kg of triazines were in the range of 2.8%-5.5% and 3.7%-7.2%, respectively. The calibration graphs were linear in the range of 3.0-500μg/kg and the limits of detection were in the range of 1.0-2.0μg/kg. The relative recoveries of different fruit and vegetable samples that have been spiked with two levels of target compounds were 91.5%-109.8%. The method has good linearity, sensitivity, accuracy, and precision. It is also environmentally friendly and was successfully used to determine the concentrations of triazines in fruit and vegetable samples.