TIAFT: AN ALTERNATIVE WORKFLOW FOR DRUG ANALYSIS

Significance of the Topic

The continual emergence of new and potentially toxic psychoactive substances poses significant analytical challenges for forensic laboratories. Traditional workflows relying on colorimetric or chromatographic screening followed by gas chromatography–mass spectrometry (GC–MS) confirmation often lead to sample backlogs and delayed reporting. Rapid, high-specificity methods are essential to accelerate case turnaround and maintain laboratory efficiency.

Objectives and Study Overview

This study evaluates an alternative two-step workflow for seized drug analysis. The first step employs atmospheric solids analysis probe–mass spectrometry (ASAP-MS) for ultra-fast screening. The second step uses ultrahigh-performance liquid chromatography–time-of-flight mass spectrometry (UPLC-TOF-MS) for definitive confirmation. The goal is to assess analytical performance, concordance between techniques, and overall suitability for forensic triage.

Instrumental Setup

• ASAP-MS System: RADIAN™-ASAP with LiveID™ software for direct sample ionisation and real-time library matching.
• UPLC-TOF-MS System: ACQUITY™ UPLC I-Class coupled to ACQUITY™ RDa™ detector with waters_connect™ (UNIFI™) informatics.

Methodology

Sample Preparation:

• Certified reference materials (CRMs) analysed directly by ASAP-MS.
• Seized tablets, powders and pills dissolved in methanol:water (50:50 v/v), diluted 1:20 for ASAP-MS screening.
• Further dilution (1:1000) in aqueous mobile phase for UPLC-TOF-MS confirmation.

ASAP-MS Screening:

• Direct sample introduction using a heated desolvation gas and corona discharge to generate protonated ions.
• Four cone voltages (15, 25, 35, 50 V) in positive mode for in-source collision-induced dissociation and spectral fingerprinting.
• Library matching via LiveID™ with a minimum match score threshold of 850/1000.

UPLC-TOF-MS Confirmation:

• Chromatographic separation on ACQUITY UPLC HSS T3 column (2.1×100 mm, 45 °C) with 9.5 min gradient (5 mM ammonium formate pH 3.0 / acetonitrile + 0.1% formic acid).
• Full-scan accurate mass acquisition (m/z 50–2000) in two functions: low-energy precursor acquisition and elevated-energy fragmentation.
• Identification based on retention time (±0.35 min), precursor mass and at least one diagnostic fragment ion.

Main Results and Discussion

CRM Analysis:

• All reference compounds achieved match scores >870 in ASAP-MS, with sensitivity and specificity exceeding 95%.

Seized Sample Analysis:

• ASAP-MS provided ≥850 match scores for one or more components in 93% of samples, yielding 74 positive identifications across seven substances.
• UPLC-TOF-MS confirmed one or more components in 95% of samples, yielding 79 identifications across eight substances (including sildenafil detected only by UPLC-TOF-MS).
• Common analytes: MDMA, ketamine, cocaine, 2C-B, flualprazolam, paracetamol, caffeine; sildenafil missed in ASAP-MS due to library limitations.
• Discordances stemmed from detection sensitivity, library coverage and threshold settings; two pharmaceutical formulations required structural elucidation after negative screening.

Benefits and Practical Applications

This workflow offers:

• Rapid screening turnaround (< seconds per sample) for high-throughput triage.
• High specificity through spectral fingerprinting and accurate mass fragmentation.
• Comprehensive confirmation enabling multi-analyte detection and structural elucidation.
• Flexibility to operate ASAP-MS and UPLC-TOF-MS as standalone or integrated systems.

Future Trends and Applications

Advancements may include larger and more diverse spectral libraries, automated algorithm improvements for unknown identification, integration of portable ASAP-MS devices for field screening, and tighter coupling with laboratory information management systems. Emerging AI-driven interpretation tools will further streamline forensic workflows and support real-time decision making.

Conclusion

The combination of ASAP-MS for ultra-fast screening and UPLC-TOF-MS for robust confirmation presents a powerful, adaptable workflow for seized drug analysis. This approach reduces analytical bottlenecks, delivers reliable identification, and enhances overall laboratory efficiency.

References

• Scientific Working Group for the Analysis of Seized Drugs (SWGDRUG). www.swgdrug.org/
• Wood M. RADIAN ASAP with LiveID—Fast, Specific, and Easy Drug Screening. Waters Application Note 720007125EN.
• Wakefield M, Todd E. Seized Drug Screening using the ACQUITY RDa Detector. Waters Application Note 720007097EN.