Distribution Characteristics And Risk Assessmentof Typical Antibiotics In Shenfu Section Of Hunhe River

Antibiotics can get into the water through various environmental media,and affect the organisms in each trophic level.In this study,take the Shenfu section of Hunhe River as the research area,sulfanilamide,quinolones and tetracycline antibiotics in the surface water as the research object.LC-MS detection method was established by optimizing the chromatographic conditions and SPE separation to determine 8antibiotics in the research area,including SD,SMX,SM₂,CIP,ENR,OFL,TC and OTC.Then the concentrations and distribution characteristics of the 8 antibiotics were analyzed.And the ecological risks of these antibiotics to different trophic species were evaluated by risk entropy method.The main·results are as follows:（1）A SPE-HPLC detection method for determining 8 antibiotics in water was established.When the flow rate was 0.25 ml/min,the injection volume was 5.0μg/L,and methanol and 0.1%formic acid were used as mobile phase respectively,the peak output effect is better.Under the optimized instrument condition,the linear equation of standard curve has fine linear correlation,and the linear range is wide,the regression coefficient R² is above 0.99.The recovery rate of standard addition is 79.91%-91.31%,and the detection limit is 0.18-0.52 ng/L,which met the requirements of quantitative analysis.（2）The distribution characteristics of 8 typical antibiotics in Shenfu section of Hunhe River were revealed.The results showed that the 4 antibiotics with the highest detection rate were SMX,CIP,OTC and TC,which the detection rate were 40%.The order of the highest concentration of 8 antibiotics was OFL（32.1 ng/L）>SMX（25.3 ng/L）>CIP（14.2 ng/L）>TC（10.1 ng/L）>OTC（8.0 ng/L）>SD（7.2 ng/L）>ENR（4.4 ng/L）>SM₂（0.7 ng/L）.The order of average content was SMX>OFL>CIP>TC>OTC>SD>ENR>SM₂.The distribution characteristics of 8 antibiotics in space were lower segment>middle segment>upper segment.The general trend of the distribution of sulfonamides,quinolones and tetracyclines in China’s rivers was quinolones>sulfonamides>tetracyclines,and the concentration of antibiotics in rivers of developed cities was generally higher than that in other general rivers,and the concentration of these 3 antibiotics in Hunhe River was generally at a low level.（3）The ecological risk of 8 typical antibiotics in Shenfu section of Hunhe River was evaluated.The results show that the 3 antibiotics:sulfonamides,quinolones and tetracyclines had some ecological risks.Among the sulfonamides,SMX was a medium risk to algae,RQ_S was 0.84.Among the quinolones,OFL was a high risk to algae,RQ_S was 1.53,higher than 1.Meanwhile,OFL was a medium risk to aquatic plants and CIP,RQ_S was 0.255 and 0.835 respectively.While tetracycline antibiotics had low risk to 3sensitive organisms:algae,invertebrates and water fleas.By analyzing the ecological risk of the 3 antibiotics in some rivers of China,we found that the order of their risk level was OFL>CIP>SMX>ENR>OTC.While the risk of SD,SM₂ and TC was at a low level,and quinolones>sulfonamides>tetracyclines.This result was consistent with that of Hunhe River,and the risk level of these 3 antibiotics in Hunhe River was lower than that in most other rivers of China.