Quantitative and Semi-Quantitative Determination of PPCPs and Their By-products in Wastewater Treatment Plants Samples Using UHPLC-Orbitrap MS and Data Mining Technologies

Importance of the Topic

Pharmaceuticals and personal care products (PPCPs) are widely used and often incompletely removed by conventional wastewater treatment. Their continuous release into aquatic environments poses risks to ecosystems and human health, requiring sensitive and comprehensive analytical strategies to monitor both parent compounds and transformation by-products.

Objectives and Study Overview

The study aimed to develop a robust analytical workflow for:

• Quantitative determination of a broad panel of PPCPs in wastewater treatment plant effluents via UHPLC-Orbitrap MS
• Semi-quantitative evaluation of PPCP degradation products and assessment of treatment conditions

This method was applied to 43 permeate samples collected from a pilot anaerobic membrane bioreactor (AnMBR) operated at 20 °C, 35 °C and 55 °C across different seasons.

Methodology and Data Analysis

Samples were concentrated via solid phase extraction using Waters Oasis HLB cartridges. Chromatographic separation employed a Thermo Scientific Dionex UltiMate 3000 HPLC with Betasil and Hypersil Gold columns under positive and negative ionization modes. Detection used an Exactive Plus Orbitrap MS with heated electrospray ionization at 140 000 resolving power. Quantification relied on deuterium‐ and 13C‐labelled internal standards, while non‐targeted screening used TraceFinder and SIEVE software with a 312‐compound database and a 5 ppm mass extraction window.

Used Instrumentation

• Waters Oasis HLB SPE cartridges (6 cc, 500 mg)
• Thermo Scientific Dionex UltiMate 3000 HPLC system (HRG-3400RS pump, WPS-3000 autosampler, TCC-3400 column compartment)
• Thermo Scientific Betasil and Hypersil Gold 2.1 × 100 mm columns
• Thermo Scientific Exactive Plus Orbitrap MS with heated ESI interface
• Thermo Scientific TraceFinder and SIEVE data analysis software

Main Results and Discussion

The workflow quantified 43 target PPCPs with high occurrence (≥ 75 %), including stimulants (caffeine), anticonvulsants (carbamazepine), insect repellents (DEET) and anti-inflammatories (diclofenac). Median concentrations ranged from tens to thousands of ng/L. Thirty by-products such as chlorophenol and acridone were detected. Principal component analysis revealed that treatment temperature had a greater impact on by-product profiles than seasonal variation. Triclosan and carbamazepine by-product patterns were further characterized, showing maximum formation at 35 °C.

Benefits and Practical Applications

This UHPLC-Orbitrap MS approach offers high sensitivity, accuracy and throughput for comprehensive monitoring of PPCPs and their transformation products. It supports environmental risk assessment, optimization of treatment processes and regulatory compliance by providing detailed occurrence data and insight into degradation pathways.

Future Trends and Potential Applications

Advancements are expected in reference standard availability for emerging by-products, expanded high-resolution MS libraries, real-time monitoring integration and coupling with predictive data-mining tools. Such developments will enhance the detection scope and mechanistic understanding of contaminant fate in diverse treatment systems.

Conclusion

A fully validated solid phase extraction–UHPLC-Orbitrap MS method was established for quantitative and semi-quantitative analysis of PPCPs in wastewater. Application to AnMBR samples demonstrated robust performance across varying operational conditions and enabled comprehensive profiling of both parent compounds and their transformation products.

References

• Ontario Ministry of the Environment. The Determination of Emerging Organic Pollutants in Environmental Matrices by Liquid Chromatography–Tandem Mass Spectrometry (LC–MS/MS), Method E3454.
• Sanchez-Prado L, Llompart M, García-Jares C, Bayona JM, Cela R. Monitoring the photochemical degradation of triclosan in wastewater by UV light and sunlight using solid-phase microextraction. Chemosphere. 2006;65(8):1338-1347.