Metrohm STRam portable Raman spectrometer

Significance of Topic

The portable Raman analyzer STRam® introduces a non-invasive approach for identifying materials through opaque barriers. This capability is critical in pharmaceuticals, customs inspection, forensic analysis and other fields where maintaining sample integrity and safety is essential.

Objectives and Study Overview

The primary goal is to demonstrate how patented STRaman® technology enables high-throughput Raman detection beneath diffusive or opaque layers. The study outlines system design, performance characteristics, and practical applications for rapid on-site material identification.

Methodology and Instrumentation

The system integrates a high-throughput spectrometer (models BWS475-785H-ST and BWS475-1064-ST), a low-noise CCD or InGaAs array detector, specialized sampling optics and advanced identification algorithms (STID). The laser source delivers up to 420 mW adjustable in 1 % increments. Sampling probes enable large area and depth interrogation with minimized power density. Software packages BWID®-Pharma and BWSpec® manage data acquisition, 21 CFR Part 11 compliance, and STID-based library matching. Optional BWIQ® provides multivariate chemometrics.

Main Results and Discussion

The STRam system successfully captures Raman signatures from materials inside plastic bottles, paper bags and other opaque containers without opening them. Depth penetration and barrier suppression algorithms allow extraction of interior spectra with minimal interference from overlying layers. Sensitivity tests confirm reliable identification of pharmaceuticals, narcotics, biological samples and energetic materials. Versatility evaluations demonstrate reproducible measurements across heterogeneous surfaces and adaptable focal configurations.

Benefits and Practical Applications

• Non-destructive through-package identification preserves sample and package integrity.
• Portable design with optional battery support enables field deployment.
• Large sampling area enhances reproducibility on heterogeneous materials.
• Low power density protects sensitive samples from laser damage.
• Comprehensive software ensures regulatory compliance and secure data handling.

Future Trends and Potential Uses

Advances may include deeper penetration optics, expanded spectral libraries for novel substances, integration with machine learning for automated anomaly detection and miniaturization for handheld form factors. Combining Raman with complementary sensors (e.g. NIR, fluorescence) could further broaden material classification capabilities.

Conclusion

The STRam portable Raman analyzer represents a significant step in non-invasive material identification across opaque barriers. Its combination of high sensitivity, barrier suppression and software-driven algorithms makes it a powerful tool for research, industrial QA/QC and security applications.

Reference

Documentation provided by B&W Tek, LLC on STRam® Raman system (Doc-Rev: 280001279-G, 2020).