Trace Detection of DMT in Plant Matter

Significance of the topic

DMT is a potent hallucinogen found in diverse plant species and its rising recreational use alongside varying legal frameworks complicates regulatory enforcement. Rapid on-site detection of DMT in plant matter is essential for consumer safety and law enforcement.

Objectives and study overview

This study demonstrates a portable surface-enhanced Raman spectroscopy (SERS) method using the Metrohm MIRA XTR DS platform to detect trace levels of DMT in ground plant bark. Two SERS approaches—colloidal gold nanoparticles and gold P-SERS strips—are evaluated for analytical sensitivity and field suitability.

Methodology

• Test samples prepared by spiking dried, milled bark with DMT at mass ratios of 0.005 to 0.1 wt%
• Extraction performed with dichloromethane by shaking and settling
• SERS analysis conducted via Au nanoparticle colloids or P-SERS strips
• Acquisition settings: 785 nm laser, relative power 5, integration time 4 s, five averages, orbital raster scanning enabled

Instrumentation Used

• MIRA XTR DS Basic package featuring 785 nm excitation, XTR algorithms for fluorescence suppression, and orbital raster scanning
• ID Kit Au P-SERS containing gold P-SERS strips, sample vials, spatula, and dropper

Main Results and Discussion

• Au NP SERS achieved a detection limit of approximately 0.005 wt% DMT by identifying characteristic Raman peaks
• Au P-SERS strips reliably detected DMT down to 0.1 wt%, suitable for higher concentration samples in field applications
• Orbital raster scanning enhanced sample coverage and measurement reproducibility

Benefits and Practical Applications of the method

The portable SERS workflow enables customs and law enforcement agents to perform rapid, minimally invasive screening of plant materials, facilitating timely interception of illicit DMT shipments.

Future Trends and Potential Applications

• Expanding spectral libraries to include additional psychoactive compounds for comprehensive field screening
• Integrating automated sample preparation for higher throughput and consistency
• Advancing SERS substrate designs to further lower detection limits
• Combining handheld Raman devices with cloud-based data analysis for enhanced portability and remote collaboration

Conclusion

The MIRA XTR DS platform, combined with Au NP and P-SERS substrates, provides a rapid, sensitive, and field-deployable solution for detecting DMT in plant materials, supporting regulatory compliance and protecting public health.

References

1. Philadelphia CBP seizes two shipments of dangerous controlled substances destined to New York and Chicago, U.S. Customs and Border Protection, 2022
2. Sixty pounds of dimethyltryptamine seized by CBP officers, U.S. Customs and Border Protection, 2022
3. Chambers MI Appley MG Longo CM et al. Detection and quantification of psychoactive N,N-dimethyltryptamine in ayahuasca brews by ambient ionization high-resolution mass spectrometry. ACS Omega 2020;5(44):28547–28554
4. N,N-dimethyltryptamine overview on ScienceDirect Topics accessed October 14 2022
5. CBP Memphis seizes over 634 pounds of DMT so far this fiscal year, U.S. Customs and Border Protection, 2022