Evaluation of wastewater treatment efficiency for emerging contaminants for non-target screening by liquid chromatography with tandem mass spectrometry

Introduction. Modern environmental monitoring requires effective methods for detecting and identifying new potentially hazardous anthropogenic contaminants, especially those not subject to standard control. High-performance liquid chromatography with tandem mass spectrometry (HPLC-MS/MS) is a promising tool for non-target screening of micropollutants in aquatic environments.

Materials and methods. A non-target screening approach using HPLC-MS/MS was applied. This involved recording mass spectra of major components in water samples (wastewater before and after treatment, drinking water) followed by comparison of experimental fragmentation spectra with reference databases (MassBank, NIST) using spectral similarity algorithms.

Results. The non-target screening method using HPLC-MS/MS enabled the detection and tentative identification of six organic compounds in wastewater samples with varying degrees of resistance to treatment. Caprolactam and 3-cyclohexyl-1,1-dimethylurea were found to be the most persistent, with removal efficiencies of 40% and 31%, respectively, indicating their high resistance to standard water treatment technologies. Other identified compounds, including lauryldiethanolamide, demonstrated removal efficiencies ranging from 93% to 98%. Identification was confirmed by matching experimental fragmentation spectra with MassBank and NIST databases. Probable sources of formation and discharge of these contaminants, along with associated environmental risks, were established.

Limitations. Final confirmation of identity and accurate quantification requires additional targeted analysis using certified reference standards.

Conclusion. The presented non-target screening approach based on liquid chromatography with tandem mass spectrometry proved effective for detecting and tentatively identifying new potentially hazardous anthropogenic contaminants in various water samples. A key result of this work was the identification of two persistent organic compounds in wastewater – caprolactam and 3-cyclohexyl-1,1-dimethylurea – which exhibited the lowest removal efficiency.

Compliance with ethical standards. The study does not require the conclusion of the Biomedical Ethics Committee.

Contribution:
Streletskiy A.V. — the concept and design of the study, experimental work, collection and processing of material, statistical processing, writing a text;
Filimonova E.I — experimental work, collection and processing of material.
All authors are responsible for the integrity of all parts of the manuscript and approval of the manuscript final version.

Conflict of interest. The authors declare no conflict of interest.

Funding. The work was completed within the framework of the state task (“Monitoring”, “Chemical Indicators 25-27”).

Received: August 15, 2025 / Accepted: November 3, 2025 / Published: December 19, 2025

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