Evaluation of the Potential of the ACQUITY QDa Mass Detector for Use in Forensic Chemistry and Drug Control Laboratories

Importance of the Topic

The implementation of rapid and cost efficient qualitative screening for pharmaceuticals is vital in forensic chemistry and drug control settings. The ability to identify active ingredients reliably supports law enforcement, regulatory compliance and public health. Advances in mass detector technology may broaden access to high performance screening methods beyond specialist laboratories.

Objectives and Study Overview

This study aimed to evaluate the transferability of an established toxicology spectral library, originally created on a triple quadrupole mass spectrometer, to a simpler quadrupole mass detector. Eight representative over the counter and prescription medicines were selected to assess qualitative identification and library matching performance.

Methodology and Instrumentation

Sample Preparation

• Tablets, capsules or 250 microliters of liquid formulations were extracted into 25 milliliters of 70:30 methanol water and sonicated for 30 minutes
• Samples were centrifuged and the supernatant was diluted with water prior to analysis
• A 10 microliter injection volume was used for LC-MS screening

Chromatographic and Detection Conditions

• System: Ultra performance liquid chromatography with a toxicology screening gradient, 15 minute run time
• Detector: Electrospray ionization in positive mode on a single quadrupole mass detector scanning m/z 80 to 650
• Cone voltages: Data collected at five voltages (10, 20, 35, 45 and 55 volts) to produce in source fragmentation patterns
• Data processing: MassLynx software with ChromaLynx application manager for peak detection and library matching

Used Instrumentation

• ACQUITY UPLC I Class System with FTN sample manager
• ACQUITY QDa Mass Detector operating in ESI positive mode
• MassLynx Software with ChromaLynx Application Manager for spectral matching

Main Results and Discussion

The quadrupole detector exhibited higher fragmentation at the same cone voltages compared to the original triple quadrupole system. Library voltages were adjusted to achieve matching fragmentation profiles. All eight medicines yielded positive identifications of their active ingredients with average match factors above 700. Azathioprine, absent from the original library, was detected in one formulation and its spectra were used to create a new library entry. Figures showed consistent fragmentation patterns and clear library browser results highlighting precursor ions and match scores.

Benefits and Practical Applications

The adapted library with the simpler mass detector provides a low cost qualitative screening solution. It offers:

• Rapid identification of pharmaceuticals in forensic and drug control laboratories
• Reduced instrument complexity and maintenance requirements
• Retention of high confidence in compound identification via multi voltage spectra

Future Trends and Opportunities

Expanding the spectral library to additional illicit and emerging compounds will broaden applicability. Integration with automated sample preparation and data processing workflows can improve throughput. Coupling qualitative screening with quantitative methods may support comprehensive forensic case work. Development of screening protocols for diverse matrices such as biological fluids or seized materials will extend utility in field and clinical settings.

Conclusion

The study demonstrates that an established toxicology library can be successfully applied to a quadrupole mass detector for reliable qualitative screening of pharmaceuticals. The modified approach delivers a cost effective, robust solution suitable for forensic and drug control laboratories.

References

1. 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 Journal of Analytical Toxicology 2010 34 571-580
2. Lee R, Wood M Systematic toxicological screening using the ACQUITY UPLC I Class Xevo TQ-S micro Application note 720005661EN Waters Corporation 2016
3. Waters Corporation ACQUITY QDa detector brochure Publication 720004632EN 2017
4. Rosano T, Wood M, Swift T Postmortem drug screening by non targeted and targeted ultra performance liquid chromatography mass spectrometry Journal of Analytical Toxicology 2011 35 411-423