Amoxicillin in Water: Insights into Relative Reactivity, Byproduct Formation, and Toxicological Interactions during Chlorination

In recent years, many studies have highlighted the consistent finding of amoxicillin in waters destined for wastewater treatment plants, in addition to superficial waters of rivers and lakes in both Europe and North America. In this paper, the amoxicillin degradation pathway was investigated by simu...

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Bibliographic Details
Main Authors: Antonietta Siciliano, Marco Guida, Giovanni Libralato, Lorenzo Saviano, Giovanni Luongo, Lucio Previtera, Giovanni Di Fabio, Armando Zarrelli
Format: Article
Language:English
Published: MDPI AG 2021-01-01
Series:Applied Sciences
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Online Access:https://www.mdpi.com/2076-3417/11/3/1076
Description
Summary:In recent years, many studies have highlighted the consistent finding of amoxicillin in waters destined for wastewater treatment plants, in addition to superficial waters of rivers and lakes in both Europe and North America. In this paper, the amoxicillin degradation pathway was investigated by simulating the chlorination process normally used in a wastewater treatment plant to reduce similar emerging pollutants at three different pH values. The structures of 16 isolated degradation byproducts (DPs), one of which was isolated for the first time, were separated on a C-18 column via a gradient HPLC method. Combining mass spectrometry and nuclear magnetic resonance, we then compared commercial standards and justified a proposed formation mechanism beginning from the parent drug. Microbial growth inhibition bioassays with <i>Escherichia coli</i>, <i>Klebsiella pneumoniae</i>, and <i>Staphylococcus aureus</i> were performed to determine the potential loss of antibacterial activity in isolated degradation byproducts. An increase of antibacterial activity in the DPs was observed compared to the parent compound.
ISSN:2076-3417