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

Liquid chromatography–tandem mass spectrometry (LC–MS/MS) has become an essential tool in clinical diagnostics due to its high sensitivity, specificity and multiplexing capability.
It enables simultaneous measurement of diverse analytes in minimal sample volumes and supports custom assay development by laboratories.

Study objectives and overview

This study aimed to evaluate the analytical performance of three novel Class I devices for general clinical use: a dual‐channel HPLC system (Prelude MD), a quadrupole tandem mass spectrometer (Endura MD) and dedicated data processing software (ClinQuan MD).
Key focus areas included system stability over extended runs, robustness under varied conditions and overall time efficiency, using spiked synthetic serum and urine matrices.

Methodology

• Sample preparation: Synthetic serum and urine were spiked with target analytes (alprazolam, reserpine, chloramphenicol, testosterone, estradiol) and matching isotopically labeled internal standards.
• Robustness study: Continuous analysis of 500 serum injections spiked with alprazolam over 24 hours, interspersed with 11 quality control samples.
• Precision study: Replicate analysis (n=40) of four compounds using heated electrospray ionization (HESI) and atmospheric pressure chemical ionization (APCI) with polarity switching.
• Solvent consumption assessment: Quantification of mobile phase usage per injection for loading and eluting solvents.

Instrumentation

• Prelude MD two‐channel HPLC equipped with TurboFlow online sample cleanup and Accucore aQ or Hypersil Gold analytical columns.
• Endura MD triple‐stage quadrupole tandem mass spectrometer operated in selected reaction monitoring mode with HESI and APCI probes.
• ClinQuan MD data processing software providing tiered user permissions (technician, supervisor, director) and built-in audit trail.

Main results and discussion

• Robustness: Retention time RSD of 0.85% and concentration RSD of 1.39% over 500 injections, with all QC values within ±2σ.
• Precision: Concentration RSD for HESI—reserpine 1.74% and chloramphenicol 4.48%; for APCI—testosterone 1.84% and estradiol 7.20%.
• Ion ratio stability: Confirming-to-quantifying ion ratios remained stable (RSD <2.5%) over 500 injections.
• Throughput optimization: Dual-channel sequencing eliminated MS idle periods and effectively doubled sample throughput.
• Solvent efficiency: Loading and eluting phase consumption was minimized (e.g. 2.83 mL for loading A, 1.87 mL for eluting A per injection).

Benefits and practical applications

The evaluated system delivers a robust, precise and high-throughput workflow suitable for routine clinical laboratories. Advantages include reduced solvent consumption, minimized downtime, streamlined data processing and flexible assay configuration, facilitating therapeutic drug monitoring and multi-analyte screening.

Future trends and potential applications

• Expanded multiplex panels for hormones, drugs of abuse and biomarkers.
• Integration with laboratory information management systems for seamless data exchange and regulatory compliance.
• Further automation and miniaturization to increase sample throughput and decrease volume requirements.
• Advanced software capabilities such as AI-driven peak detection and automated anomaly flagging.

Conclusion

The integrated Prelude MD HPLC, Endura MD mass spectrometer and ClinQuan MD software demonstrated excellent robustness, precision and operational efficiency for general clinical LC–MS/MS applications, supporting extended 24-hour runs with consistent quantitation and low solvent usage.

References

No external literature references were cited in the original document.