Rapid Analysis of Drugs in Forensic Specimens Using the DPiMS-8060

Significance of the Topic

The rapid and reliable detection of drugs and toxic substances in human tissues is critical in forensic investigations where traditional fluid sampling is not possible. Organs from decomposed, charred, or hemorrhagic remains often require complex and time-consuming pretreatment. A faster, simplified approach can greatly enhance case turnaround and decision making in forensic laboratories.

Objectives and Overview of the Study

This study evaluates a newly developed mass spectrometer platform (DPiMS-8060) combining probe electrospray ionization (PESI) with tandem mass spectrometry for direct analysis of drug residues in organ tissue. Focusing on the synthetic narcotic MT-45, the work addresses both qualitative identification and quantitative determination without extensive sample cleanup.

Methodology and Instrumentation

The key steps are:

• Sample preparation: 3 mm square sections of liver, brain, kidney, heart, and lung.
• Minimal pretreatment: deposition of 35 µL of 1:1 ammonium formate (10 mmol/L) and ethanol solution on each tissue piece.
• Probe electrospray ionization: a steel probe repeatedly pierces the tissue section, followed by application of high voltage to ionize adhered analytes.
• Mass spectrometry: product ion scanning over m/z 50–450 with 25 V collision energy and 405 u/sec scan speed.

Key Results and Discussion

Qualitative analysis demonstrated clear detection of MT-45 parent ion (m/z 181) and its characteristic fragments (m/z 169, 103, 349) in all organs. Expected metabolites, including mono- and di-hydroxylated forms, were also observed in liver tissue scans. Quantitative performance was benchmarked against a conventional LC-MS/MS method using QuEChERS-prepared extracts:

• Calibration linearity: r² = 0.9991 by standard addition (0–550 ng/mL).
• Accuracy: relative error within –5.0 to +9.4 % across six calibration levels.
• Concentration agreement: DPiMS-8060 vs. LC-MS/MS results differed by less than 10 % in each organ.
• Analysis time: 0.5 min per sample vs. 20 min for LC-MS/MS (97.5 % reduction).

Benefits and Practical Applications

The DPiMS-8060 approach eliminates lengthy extraction, cleanup, and chromatography steps. Its minimal sample pretreatment and fast measurement cycle make it highly suitable for forensic casework where rapid turnaround is required. Comparable accuracy to established LC-MS/MS methods affirms its suitability for quantitative determinations in complex tissues.

Future Trends and Opportunities

Further developments may include expanding the library of target compounds, automating probe sampling for high-throughput workflows, and integrating PESI-MS platforms into field-deployable units for on-site forensic screening. Continued validation across a broader range of analytes and matrix types will support wider adoption in toxicology and regulatory laboratories.

Conclusion

The combination of probe electrospray ionization and tandem mass spectrometry on the DPiMS-8060 enables rapid, accurate detection and quantitation of narcotics in organ tissues with minimal pretreatment. This method offers a compelling alternative to time-intensive LC-MS/MS workflows, accelerating forensic analyses and supporting timely investigative outcomes.

Reference

Usui K.; Murata T.; et al. Drug Testing and Analysis 2018, 10, 1033–1038.