Through-container analysis with Raman spectroscopy

Importance of the Topic

The ability to identify materials inside sealed containers without opening them represents a significant advance in analytical chemistry and field screening.
This non-invasive approach enhances operator safety by preventing direct contact with potentially hazardous substances.
It also streamlines workflows in law enforcement, customs, first response, and industrial quality control by delivering rapid, accurate results at the point of need.

Objectives and Study Overview

This application note describes the development and validation of through-container Raman analysis using the Metrohm TacticID-1064 ST handheld system.
Key objectives include demonstrating the device’s capability to penetrate various packaging materials, accurately distinguish container signals from sample spectra, and identify a broad range of substances in real-time.
The study examines performance with paper, plastic, and glass barriers, assesses sampling attachments, and presents representative test cases.

Methodology and Instrumentation

The TacticID-1064 ST employs a 1064 nm laser excitation source paired with a specialized See-Through (ST) Smart Attachment to collect Raman spectra through opaque or multi-layer packaging.
An advanced algorithm separates container and content signatures, matching the content spectrum against an extensive onboard library.
Additional attachments include:

• General Attachment for solids, gels, and liquids in transparent containers (5.5 mm working distance).
• Long Working Distance (LWD) Attachment for thick-walled bottles (8 mm working distance).
• Short Working Distance (SWD) Attachment for thin, transparent vials and surface measurements.

Main Results and Discussion

Tests on narcotic cutting agents (caffeine, mannitol), common powders (sodium bicarbonate), pharmaceuticals (aspirin, acetaminophen), and liquids (absinthe, cyclohexane) showed clear identification through multilayer plastic, glass vials, and paper envelopes.
The ST Attachment successfully separated container interference, delivering match scores in seconds.
PDF reports overlay sample and reference spectra, visually confirming identification and container rejection.

Benefits and Practical Applications

Through-container Raman analysis offers:

• Enhanced safety by avoiding direct exposure to unknown or hazardous substances.
• Operational efficiency with rapid, on-site screening and 100% inspection of incoming goods in manufacturing.
• Flexibility for first responders, customs agents, and QA/QC teams to perform quality checks without sample preparation.

Future Trends and Potential Uses

Emerging developments may include integration with artificial intelligence for automated spectral interpretation, expansion of spectral libraries to cover novel threats and advanced materials, and further miniaturization of spectrometers for wearables.
Application of through-container Raman in pharmaceutical packaging verification, counterfeit detection, and environmental monitoring is also anticipated.

Conclusion

The Metrohm TacticID-1064 ST represents a versatile tool for non-destructive, through-container material identification.
Its combination of 1064 nm excitation, smart attachments, and robust algorithms delivers fast, reliable results across diverse scenarios, improving safety and workflow efficiency.

References

• Metrohm Application Note AN-RS-046: Through-container analysis with Raman spectroscopy.