Fluoroquinolones in Hospital Wastewater: Analytical Method, Occurrence, Treatment with Ozone and Residual Antimicrobial Activity Evaluation

Fluoroquinolones antimicrobials are partially excreted in natura after administration. Their occurrence was investigated in hospital raw sewage (HRS) and treated wastewater (TW) using an online solid phase extraction-ultra high-performance liquid chromatography-tandem mass spectrometry method (SPE-UHPLC-MS/MS). The analytical curves ranged from 0.25 to 46 ng mL-1 and the matrix effect, assessed for marbofloxacin and lomefloxacin, ranged from –63 to +1%. All HRS samples contained ciprofloxacin (1-34 ng mL-1) and ofloxacin (0.9-27 ng mL-1), while norfloxacin was detected in 17% of the samples (0.8-4.4 ng mL-1). Only ciprofloxacin (0.5-5.6 ng mL-1) was detected in TW samples. The antimicrobial activity of the HRS samples for E. coli was higher than a ciprofloxacin solution of 1 mg L-1, due to the presence of other antimicrobial agents. Ozonation (10 mg O3 L-1 min-1 ; 10 min) degraded up to 84% of the fluoroquinolones and removed the antimicrobial activity of HRS samples.

氟喹诺酮类抗菌药物（fluoroquinolones antimicrobials）经给药后，会有部分以原生形态被排泄出体内。本研究采用在线固相萃取-超高效液相色谱-串联质谱法（online solid phase extraction-ultra high-performance liquid chromatography-tandem mass spectrometry, SPE-UHPLC-MS/MS），对医院原污水（hospital raw sewage, HRS）与处理后废水（treated wastewater, TW）中该类药物的赋存情况进行了调查。该方法的标准曲线线性范围为0.25~46 ng·mL⁻¹；以马波沙星和洛美沙星为受试物评估得到的基质效应区间为-63%~+1%。所有医院原污水样品中均检出环丙沙星（1~34 ng·mL⁻¹）与氧氟沙星（0.9~27 ng·mL⁻¹），诺氟沙星则仅在17%的样品中被检出，浓度范围为0.8~4.4 ng·mL⁻¹。处理后废水样品中仅检出环丙沙星，浓度区间为0.5~5.6 ng·mL⁻¹。由于存在其他抗菌成分，医院原污水样品对大肠杆菌（E. coli）的抗菌活性高于1 mg·L⁻¹的环丙沙星标准溶液。采用臭氧氧化工艺（臭氧投加速率为10 mg O₃·L⁻¹·min⁻¹，反应时间10 min）可降解最高达84%的氟喹诺酮类抗菌药物，并完全消除医院原污水样品的抗菌活性。