Rapid and high-throughput detection of 82 herbicides in agricultural irrigation water by UPLC-QTRAP-MS/MS with large volume direct injection

• A perfect strategy for the analysis of herbicides in irrigation water was validated. • Final LVDI-UPLC-QTRAP-MS/MS method was a pretreatment-free method for the simultaneous quantification of herbicides. • Compared with reported methods, the strategy of this study provided satisfactory recoveries and low LOD. • This method has been successfully applied in the analysis of real irrigation water samples. A rapid and high-throughput method for the detection of 82 herbicides in the water of the lake used for agricultural irrigation based on ultra-performance liquid chromatography-quadrupole linear ion trap mass spectrometry (UPLC-QTRAP-MS/MS) involving large-volume direct injection（LVDI）was established. Combining the convenience of LVDI and the high sensitivity of UPLC-QTRAP-MS/MS, the optimized method was developed without pretreatment. The results showed that most herbicides showed good linearity in the concentration range of 0.01 ∼ 5.0 μg/L, and the limits of detection (LOD) were in the range of 0.003 ∼ 0.01 μg/L. The precision of the method provided RSD values below 14.3 %, and the accuracy was demonstrated by the spiked recovery test, with recoveries ranging from 71.8 % to 117.9 %. The method was applied to irrigated water samples taken from different points at five agricultural planting bases in Shanghai. A total of 7 herbicides were detected, and the ones at higher concentrations were pretilachlor and prometryn (1.48 μg/L and 9.98 μg/L, respectively). Compared with other recent methods, the method has a lower LOD and similar recoveries and precision than other reported methods. This study provides a perfect LVDI coupled to UPLC-QTRAP-MS/MS strategy for agricultural irrigation water quality monitoring and has excellent potential for application in water safety, especially pesticide residues.