Contactless Material Verification and Identification

Significance of the Topic

Portable vibrational spectroscopy enables rapid in-field material verification, reducing logistics and contamination risks during sample transport. Handheld Raman instruments facilitate safe analysis of unknown or hazardous samples through packaging, supporting quality assurance, customs control, and industrial processes with immediate results and 100 percent inspection coverage.

Study Objectives and Overview

This product note presents the BRAVO Contactless Raman spectrometer, evaluating its performance for through-barrier material identification and verification. Key aims include demonstrating fluorescence suppression, assessing spectral accuracy, comparing dual laser excitations, and exploring measurement strategies for various packaging types.

Methodology and Instrumentation

• Technique: Handheld Raman spectroscopy with dual laser excitation at 785 and 1064 nm covering 300–3200 cm-1.
• DuoLaser excitation for extended spectral range and optimal sensitivity.
• SSE TM algorithm for efficient fluorescence mitigation from samples and packaging.
• Variable focus measurement tips for alignment with films, thin bags, and thicker containers.
• Remote operation via WiFi or Ethernet for flexible field deployment.

Key Results and Discussion

• Packaging Impact: Absorption by amber glass leads to 95–98 percent sensitivity loss, dramatically increasing measurement time and limiting use of dark or thick containers for routine checks.
• Clear Barriers: Transparent materials allow near-lossless Raman transmission; measurement depth is determined by focus geometry and tip design.
• Focus Depth Trade-off: Deeper focus can reduce packaging background but also lowers analyte signal due to absorption, requiring longer acquisitions.
• Fluorescence Suppression: SSE TM effectively extracts Raman signatures from highly fluorescent matrices, as shown for ammonium sulfate in fluorescent glass.
• Through-Barrier Identification: BRAVO achieved matching spectra of 1-hexanol in clear and amber vessels when focus and processing were optimized, despite a twelve-fold increase in acquisition time for amber.

Benefits and Practical Applications

• Field-deployable material verification for QA/QC, customs, and safety screening.
• Non-invasive analysis through packaging reduces contamination and user exposure to toxins.
• Immediate, laboratory-quality results support high-throughput workflows and regulatory compliance.
• Flexible measurement tips and advanced processing ensure robust identification across diverse packaging formats.

Future Trends and Opportunities

Handheld Raman technology will evolve with improved sensitivity, adaptive optics for deeper penetration, advanced algorithms for mixed signal deconvolution, and integration with modalities such as spatially offset Raman spectroscopy. Novel excitation sources and enhanced automation will broaden applications in smart manufacturing, field forensics, and remote monitoring.

Conclusion

BRAVO’s combination of dual excitation, fluorescence mitigation, and variable focus tips offers a powerful solution for contactless material analysis. While absorption by colored or thick containers remains a practical constraint, optimized methods enable reliable in-field identification, streamlining quality workflows and ensuring user safety.

References

1. Bruker Product Note T30 03/16 Accuracy is crucial The starting point for a robust transfer of methods
2. Bruker Product Note R34 05/16 Advanced Data Acquisition and Evaluation in Handheld Raman Spectroscopy
3. Bruker Product Note T29 12/15 Efficient mitigation of fluorescence in Raman spectroscopy using SSE TM