宁夏第三排水沟中抗生素的污染特征与生态风险评估

利用固相萃取-超高效液相色谱-静电场轨道肼质谱联用仪检测分析了宁夏第三排水沟中磺胺类、四环素类、大环内酯类、喹诺酮类和林可霉素类这5类9种抗生素的污染水平，探讨了抗生素浓度与水质指标的相关性，并评估其生态风险.结果表明，在第三排水沟及其汇入水流中共检出7种抗生素，总浓度范围分别为14.91～153.48 ng·L^-1和ND～39.37 ng·L^-1.排水沟中克拉霉素、左氧氟沙星、环丙沙星和林可霉素的检出率均为100%,检出浓度最高的为左氧氟沙星(0.84～94.12 ng·L^-1),其次为林可霉素(11.15～48.13 ng·L^-1).从空间分布上来看，第三排水沟在流经平罗县城所在地后水中抗生素总浓度显著增加，并呈现上升趋势，最大值出现在惠农段，随后，呈现下降趋势.入黄口抗生素总浓度为20.26 ng·L^-1.相关性分析表明，左氧氟沙星与NH⁺₄-N和TN呈显著的正相关关系（P<0.01）,红霉素与TN、克拉霉素与NH

Contamination Characteristics and Ecological Risk Assessment of Antibiotics in the Third Drain of Ningxia

Solid-phase extraction and ultra-high performance liquid chromatography-electrostatic field orbit hydrazine mass spectrometry were used to detect and analyze the contamination of nine antibiotics including sulfonamides, tetracyclines, macrolides, quinolones, and lincomycin in the third drain of Ningxia. Correlations between the antibiotic concentration and water quality indexes were explored, and the ecological risks were evaluated. The results showed that seven antibiotics were detected in the third drain and its confluent stream, with the total concentrations of 14.91-153.48 ng·L^-1 and ND-39.37 ng·L^-1, respectively. The detection ratios of clarithromycin, levofloxacin, ciprofloxacin, and lincomycin were 100% in the third drain. The highest-concentration antibiotic was levofloxacin (0.84-94.12 ng·L^-1), followed by lincomycin (11.15-48.13 ng·L^-1). Based on the spatial distribution analysis, after flowing through Pingluo County, total antibiotic concentrations in the third drain increased significantly and showed an increasing trend. The maximum concentration appeared in the Huinong section and showed a decreasing trend downstream. The total concentration of antibiotics before flowing into the Yellow River was 20.26 ng·L^-1. Correlation analysis showed that levofloxacin was significantly positively correlated with NH₄⁺-N and TN (P<0.01), erythromycin was significantly correlated with TN, and clarithromycin was significantly correlated with both NH₄⁺-N and TN (P<0.05), which indicated that water quality index was closely related to antibiotic concentration. The results of the ecological risk assessment showed that levofloxacin and clarithromycin in the third drain posed certain ecological risks.