Routine, Targeted and Non-Targeted Analysis of Environmental Contaminants of Emerging Concern – Development and Validation of a UHPLC Orbitrap MS Method

Importance of the Topic

The presence of contaminants of emerging concern in wastewater poses risks to human health and aquatic ecosystems. Comprehensive monitoring that integrates both targeted quantitation and non-targeted screening is essential to detect known analytes and discover new transformation products without prior reference standards.

Study Objectives and Overview

This work aimed to develop and validate a unified method for targeted analysis of 61 priority CECs and non-targeted screening of up to 312 suspects in wastewater treatment plant samples. The approach combines solid phase extraction, ultrahigh performance liquid chromatography, high-resolution Orbitrap mass spectrometry, and advanced software workflows to achieve rapid, high-confidence results without requiring authentic standards for non-targeted compounds.

Methodology and Instrumentation

The sample preparation used Oasis HLB SPE cartridges to concentrate analytes from grab samples collected at multiple WWTP process stages. Instrumentation included a Thermo Scientific Dionex UltiMate 3000 UHPLC system with Betasil and Agilent XDB C18 columns, interfaced to a Thermo Exactive Plus Orbitrap mass spectrometer via heated ESI. Data were acquired at 140 000 resolving power with automatic gain control, and processed with Thermo TraceFinder software for both quantitative target analysis and suspect screening.

Key Results and Discussion

• Targeted analysis detected 21 out of 61 compounds above method detection limits, with frequent findings of bisphenol A, caffeine, carbamazepine and hydrocortisone across ten WWTP samples.
• Non-targeted screening identified 48 high-abundance suspects including benzotriazoles, pharmaceuticals such as venlafaxine, tramadol, transformation products of carbamazepine, perfluorinated acids, and sucralose, with occurrence rates of 60–100 %.
• A case of false positive for desethylatrazine illustrated the necessity of inspecting isotopic patterns and fragment ions to avoid misidentification when retention time reference is unavailable.

Benefits and Practical Applications

• Single, streamlined workflow reduces analysis time to approximately 65 s per sample for screening.
• High mass accuracy and isotopic confirmation enhance confidence in both quantitative and tentative identifications.
• Method supports regulatory monitoring, treatment efficiency evaluation and environmental risk assessment.

Future Trends and Potential Applications

• Integration of tandem mass spectrometry and expanded spectral libraries for definitive structure elucidation.
• Use of machine learning to prioritize non-targeted features and predict transformation pathways.
• Deployment of compact high-resolution MS for on-site monitoring in field laboratories.
• Coupling suspect screening data with toxicity assays for comprehensive risk profiling.

Conclusion

The validated UHPLC-Orbitrap MS method with TraceFinder software delivers robust, high-throughput analysis of emerging contaminants, enabling reliable targeted quantitation and comprehensive suspect screening in complex wastewater matrices.

References

1. Ontario Ministry of the Environment Method E3454 Determination of Emerging Organic Pollutants by Liquid Chromatography Tandem Mass Spectrometry.
2. SANCO 12495/2011 Method Validation and Quality Control Procedures for Pesticide Residues Analysis in Food and Feed.