| The widespread and frequent application of herbicides has led to the accumulation of these chemical residues in the soil and aquatic environment,and herbicide residues in soil can sink into surface water through rainwater scouring and surface runoff,destabilizing water ecosystems.In addition,residual herbicides in water bodies may cause irreversible ecological impacts and health risks,and the problem of herbicide pollution in the water environment should not be underestimated.The environmental quality of water sources is an important barrier to ensure the safety of people’s daily drinking water,therefore,it is important to carry out the determination of herbicide residues in drinking water sources for the prevention and control of early warning of water sources.In this study,Amide herbicides（AHs）and Triazine herbicides（THs）were used as the research objects,and 11sampling points were established in the Hutuo River from Pingshan to Shenze as the research area,according to the natural conditions of the river,possible pollution sources and the existing national and provincial control monitoring sections.Surface water samples were collected in December 2021（dry period）,April 2022（flat period）and September 2022（rich period）,and the concentrations of AHs and THs were determined by solid phase extraction（SPE）-gas chromatography tandem triple quadrupole mass spectrometry（GC-MS/MS）and ultra-high performance liquid chromatography tandem triple quadrupole mass spectrometry（UHPLC-MS/MS）,and the water quality parameters of the samples were measured.The correlations between AHs and THs concentrations and water quality parameters were analyzed,and the distribution characteristics of the two typical herbicides were revealed using principal component analysis（PCA）:1)The detection rate of 19 target herbicides was 84.21%,and the average concentrations of single herbicides were below 10.0 ng·L-1.The concentrations of AHs and THs in the surface water of the study river ranged from ND～11.76 ng·L-1and ND～18.91 ng·L-1,respectively;the maximum concentration of herbicides in the midstream water of the river was 106.77 ng·L-1,and the concentration detected in the samples taken from the reservoir area of the drinking water source was high,with acetochlor（ACE）and atrazine（Atz）as the main contaminants.2)In terms of their spatial and temporal distribution characteristics,the sum of the concentrations of residual AHs and THs in the water in different periods showed a gradual increase from the flat water period(235.26 ng·L-1)>the dry water period(148.40ng·L-1)>the rich water period(88.27 ng·L-1),and showed a The trend of gradual increase from upstream to downstream of the river is mainly influenced by precipitation,river transport and agricultural production cultivation in the surrounding areas.3)Surface water quality parameters in the Shijiazhuang section of the Hutuo River basin differ in distribution in different regions,with total nitrogen（TN）showing a high level in the Yei River,dissolved oxygen（DO）showing a high level in the Liulin River,and small differences in the remaining factors.The correlation analysis showed that the target herbicides in surface water were significantly correlated with water temperature（T）,TN,DO and total phosphorus（TP）;Atz and propazine（PRO）were significantly correlated with TP and TN（p<0.05）;propazine（Prp）was significantly correlated with TP and TN（p<0.05）.propazine（Prp）and PRO were negatively correlated with temperature（p<0.01）.4)The ecological risk entropy values indicated that AHs in surface water of Hutuo River basin were generally at low risk level,while THs in water had moderate ecological risk;for human health risk,the risk quotient（RQ）of all target herbicides in river surface water,the total RQs of each sample and the RQs of 12 life stages were much less than the0.2 threshold,indicating that there was no hazard in drinking water at any stage of life.The RQs of the early life stages were 3～6 times higher than those of the adult stage. |
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