Determination and Confirmation of Triazine Herbicides and Their Degradation Products in Seawater by Liquid Chromatography Coupled With Quadrupole/Exactive Orbitrap Mass Spectrometry

Herbicides seriously threaten the ecosystem due to their wide application and environmental migration. Nevertheless, the detection and confirmation methods of triazine herbicides and their degradation products in seawater matrix remain deficient, which affect the accuracy of marine environment and aquatic organism safety risk assessment. In the present study, rapid analysis and accurate identification of seven triazine herbicides and six degradation products in seawater were achieved for the first time, based on hydrophilic-lipophilic balance solid-phase extraction combined with scanning pattern of full scan mass spectrometry-data-dependent mass spectrometry² and internal standard calibration by liquid chromatography coupled with Quadrupole/Exactive Orbitrap high-resolution mass spectrometry. The results showed a good linear relationship for the tested compounds with R² > 0.995. The limits of detection and quantitation of the method were 5.0 and 20 ng/L, respectively. The recoveries of the 13 compounds ranged from 70.0% to 120% when spiked at three levels, and the relative standard deviations were all less than 15% (n = 6). This method has been successfully applied to the detection of triazine herbicide in 34 real seawater samples, and the presence of prometryn, 2-hydroxy prometryn, desisopropyl prometryn, atrazine, and desisopropyl atrazine in positive seawater samples was confirmed by Quadrupole/Exactive Orbitrap high-resolution mass spectrometry. Therefore, the present method has promising application prospects in the detection and positive identification of pollutants in seawater, with high accuracy, sensitivity, and good reproducibility.