Evaluation of the DART QDa System for Forensic Drug Screening

Importance of the Topic

Rapid and reliable screening of seized drug materials is essential to public safety and efficient case processing. Traditional chromatographic methods, while accurate, often require lengthy run times and extensive sample preparation. The increasing variety of novel psychoactive substances (NPS) further strains forensic laboratories, creating a need for ultra-fast screening tools that can handle large sample volumes with minimal operator input.

Objectives and Study Overview

This study evaluates the feasibility of using the Direct Analysis in Real Time (DART) QDa System as a first-line forensic drug screening technique. The investigation covers qualitative detection of standard drugs at various concentrations and the analysis of real-world confiscated samples from a UK music festival. Results are benchmarked against a reference spectral library and confirmed by an orthogonal UPLC-QTof approach.

Methods and Instrumentation

The DART QDa System was equipped with a rail-based transmission module and QuickStrip™ cards holding up to 12 samples. Certified reference standards (amphetamine, clonazepam, cocaine, ketamine, MDA, morphine, naproxen, sertraline, and THC) were prepared at 50 µg/mL in methanol. Samples were spotted (3 µL) onto the card, air-dried, and introduced into the DART source. Key DART parameters were positive ion mode, helium at 300 °C, and rail speed of 1 mm/s. The QDa detector acquired full-scan MS data across m/z 60–650 at multiple cone voltages (15, 30, 50, and 70 V), with 5 Hz sampling.

Main Results and Discussion

Using PIMISA software for spectral matching against an 800-compound library, all individual standards were identified with average match scores exceeding 89%. Binary mixtures of cocaine and clonazepam at varied ratios yielded match confidences above 90%. Analysis of confiscated tablets revealed ketamine, MDMA, cocaine, sildenafil, and paracetamol either singly or in combination. Rapid screening times (5 s per sample) and minimal preparation illustrated the system’s high throughput capabilities. All putative identifications were confirmed by UPLC-QTof analysis, demonstrating concordance between methods.

Benefits and Practical Applications

• Ultra-fast throughput: individual analyses in seconds without chromatography
• Minimal sample preparation: direct spotting and air-drying
• High confidence identification: multi-cone voltage matching against an extensive library
• Versatility: effective for standards, mixtures, and real seized samples
• Workload reduction: potential to triage samples prior to confirmatory testing

Future Trends and Potential Applications

Expanding spectral libraries to include emerging NPS will further improve detection capabilities. Integration with automated sample handling and data-driven chemometric tools could enhance identification of unknown compounds. Adoption in field or mobile laboratories may provide real-time intelligence during public events, aiding harm reduction and law enforcement.

Conclusion

The DART QDa System offers a rapid, high-throughput screening solution for forensic drug analysis. Its ease of use, minimal preparation, and strong agreement with confirmatory UPLC-QTof data render it a valuable tool for preliminary identification of illicit substances.

References

• United Nations Office on Drug and Crimes. World Drug Report 2017, Amphetamine-Type Stimulants and New Psychoactive Substances.
• European Monitoring Centre for Drugs and Drug Addiction. European Drug Report, Trends and Developments, 2016.
• Waters Corporation. ACQUITY QDa Detector Brochure, 720004632EN, 2016.
• Waters Corporation. Evaluation of the Potential of the ACQUITY QDa Mass Detector for Use in Forensic Chemistry and Drug Control Laboratories, 720006004EN, 2017.
• Rosano TG, Swift TA, Wood M. Postmortem Drug Screening by Non-Targeted and Targeted UPLC-MS. J. Anal. Toxicol. 2011;35:411–423.
• Waters Corporation. Systematic Toxicological Screening Using the ACQUITY UPLC I-Class/Xevo TQ-S micro, 720005661EN, 2016.
• Chernetsova ES, Morlock GE. Determination of Drugs and Drug-Like Compounds with DART-MS. Mass Spectrom. Rev. 2011;30:875–883.