Forensic Toxicology Screening Using the ACQUITY UPLC I-Class System with the Xevo TQD

Significance of the Topic

Forensic toxicology laboratories require robust screening strategies to identify a broad spectrum of toxicants in complex biological matrices such as ante- and post-mortem specimens. The latest generation of UPLC/MS instrumentation offers enhanced sensitivity, reduced sample dispersion, and advanced data acquisition capabilities, which are critical for reliable detection and confirmation of drugs and their metabolites in forensic investigations.

Objectives and Study Overview

This study aimed to evaluate the performance of the ACQUITY UPLC I-Class System coupled with the Xevo TQD mass spectrometer for two complementary toxicological screening approaches:

• A targeted multiple reaction monitoring (MRM) method for 178 priority analytes
• A non-targeted full-scan MS method using a spectral library of over 950 substances

The main goals were to assess chromatographic transferability, sensitivity improvements, and the applicability of existing methods on the new platform.

Methodology

Authentic human urine samples underwent liquid–liquid extraction and were transferred to low-volume recovery vials. Chromatographic separation was achieved on an ACQUITY UPLC HSS C18 column (2.1 × 150 mm, 1.8 μm) at 50 °C with a 15-minute gradient from 13% to 95% organic mobile phase at 400 μL/min. The Xevo TQD operated in positive electrospray mode for MRM and both positive/negative modes for full-scan acquisition. Targeted analyses used two transitions per compound, organized into 30 time windows to maintain adequate data points. Full-scan data were acquired at seven cone voltages and searched against the existing spectral library using ChromaLynx.

Used Instrumentation

• ACQUITY UPLC I-Class System with Flow-Through Needle (FTN)
• Xevo TQD triple quadrupole mass spectrometer
• ACQUITY UPLC HSS C18 analytical column
• Waters Total Recovery Vials
• MassLynx software with TargetLynx™ and ChromaLynx™

Main Results and Discussion

System suitability tests confirmed retention times within ±0.3 min of expected values, demonstrating successful method transfer. In targeted MRM screening of a routine urine sample, key analytes (e.g., methadone, EDDP, cocaine, benzoylecgonine) were detected with increased peak areas compared to the previous system, indicating enhanced sensitivity. Full-scan screening identified additional compounds (e.g., N-desmethyl mirtazapine, xylometazoline) not included in the MRM panel, verifying library compatibility and enabling retrospective data mining. Advanced features on the Xevo TQD—Product Ion Confirmation scanning (PICs) and RADAR—allowed differentiation of isobaric isomers (hydromorphone vs morphine) and simultaneous collection of full-scan data during MRM runs to reveal unexpected analytes.

Benefits and Practical Applications

• Seamless transfer of established screening methods to a next-generation platform with minimal adjustment
• Improved chromatographic performance via reduced system volume and enhanced pre-heating
• Greater sensitivity and selectivity for target compounds
• Comprehensive full-scan capabilities for broad-spectrum screening and retrospective analysis
• Data-directed acquisition tools (PICs, RADAR) for confirmatory identification and method troubleshooting

Future Trends and Opportunities

Continued expansion of spectral libraries will further extend non-targeted screening capabilities. Integration of high-throughput workflows with automated data processing and artificial intelligence–driven interpretation could streamline forensic analyses. Emerging acquisition modes and enhanced software algorithms will enable even broader compound coverage and faster, more reliable toxicological screening.

Conclusion

The ACQUITY UPLC I-Class System coupled with the Xevo TQD provides a powerful and flexible platform for forensic toxicology screening. Existing targeted and non-targeted methods transfer readily to the new hardware, delivering heightened sensitivity, reduced carryover, and advanced acquisition features that support confident compound identification. Laboratories can customize and expand methods to meet evolving analytical requirements, although full validation is recommended before routine implementation.

Reference

1. Roberts M, Lee R, Wood M. Targeted MRM Screening for Toxicants in Biological Samples by UPLC/MS/MS. Waters Application Note 720002749EN.
2. Lee R, Roberts M, Paccou A, Wood M. Development of a New UPLC/MS Method for Systematic Toxicological Analysis. Waters Application Note 72002905EN.
3. Humbert L, Grisel F, Richeval C, Lhermitte M. Screening of Xenobiotics by Ultra-Performance Liquid Chromatography–Mass Spectrometry Using In-Source Fragmentation at Increasing Cone Voltages: Library Constitution and an Evaluation of Spectral Stability. Journal of Analytical Toxicology. 2010;34.
4. Rosano TG, Wood M, Swift TA. Postmortem Drug Screening by Non-Targeted and Targeted UltraPerformance Liquid Chromatography-Mass Spectrometry Technology. Journal of Analytical Toxicology. 2011;35.
5. ACQUITY UPLC I-Class System Brochure. Waters Brochure 720003290EN.
6. Xevo TQD Brochure. Waters Brochure 720003953EN.