Catalan Institute for Water Research (ICRA), H2O Building, Scientific and Technological Park of the University of Girona, Emili Grahit 101, E-17003 Girona, Spain.
Chemical, Biological and Environmental Engineering Department, Universitat Autònoma de Barcelona (UAB), E-08193 Bellaterra, Spain.
J Chromatogr A. 2018 Sep 21;1568:57-68. doi: 10.1016/j.chroma.2018.06.027. Epub 2018 Jun 11.
The evaluation of wastewater treatment capabilities in terms of removal of water pollutants is crucial when assessing water mitigation issues. Not only the monitoring of target pollutants becomes a critical point, but also the transformation products (TPs) generated. Since these TPs are very often unknown compounds, their study in both wastewater and natural environment is currently recognized as a tedious task and challenging research field. In this study, a novel automated suspect screening methodology was developed for a comprehensive assessment of the TPs generated from nine antibiotics during microalgae water treatment. Three macrolides (azithromycin, erythromycin, clarithromycin), three fluoroquinolones (ofloxacin, ciprofloxacin, norfloxacin) and three additional antibiotics (trimethoprim, pipemidic acid, sulfapyridine) were selected as target pollutants. The analysis of samples was carried out by direct injection in an on-line turbulent flow liquid chromatography-high resolution mass spectrometry (TFC-LC-LTQ-Orbitrap-MS/MS) system, followed by automatic data processing for compound identification. The screening methodology allowed the identification of 40 tentative TPs from a list of software predicted intermediates created automatically. Once known and unknown TPs were identified, degradation pathways were suggested considering the different mechanisms involved on their formation (biotic and abiotic). Results reveal microalgae ability for macrolide biotransformation, but not for other antibiotics such as for fluoroquinolones. Finally, the intermediates detected were included into an in-house library and applied to the identification of tentative TPs in real toilet wastewater treated in a microalgae based photobioreactor (PBR). The overall approach allowed a comprehensive overview of the performance of microalgae water treatment in a fast and reliable manner: it represents a useful tool for the rapid screening of wide range of compounds, reducing time invested in data analysis and providing reliable structural identification.
在评估水缓解问题时，评估废水处理能力对于去除水中污染物至关重要。不仅目标污染物的监测成为一个关键点，而且还生成了转化产物 (TPs)。由于这些 TPs 通常是未知的化合物，因此目前它们在废水和自然环境中的研究被认为是一项繁琐的任务和具有挑战性的研究领域。在这项研究中，开发了一种新颖的自动化可疑物筛选方法，用于全面评估微藻水处理过程中生成的九种抗生素的 TPs。选择了三种大环内酯类抗生素（阿奇霉素、红霉素、克拉霉素）、三种氟喹诺酮类抗生素（氧氟沙星、环丙沙星、诺氟沙星）和三种其他抗生素（甲氧苄啶、吡哌酸、磺胺嘧啶）作为目标污染物。通过直接注射在线湍流流动色谱-高分辨率质谱 (TFC-LC-LTQ-Orbitrap-MS/MS) 系统对样品进行分析，然后自动进行数据处理以进行化合物鉴定。筛选方法允许从自动创建的软件预测中间体列表中鉴定出 40 种暂定 TPs。一旦识别出已知和未知的 TPs，就会考虑到它们形成的不同机制（生物和非生物）来提出降解途径。结果表明，微藻具有大环内酯类生物转化的能力，但不具有其他抗生素（如氟喹诺酮类抗生素）的能力。最后，将检测到的中间体包含在内部库中，并应用于在基于微藻的光生物反应器 (PBR) 中处理的实际厕所废水中暂定 TPs 的鉴定。总体方法能够快速可靠地全面了解微藻水处理的性能：它是一种快速筛选广泛化合物的有用工具，减少了数据分析投入的时间，并提供了可靠的结构鉴定。
