Metrohm STRam portable Raman spectrometer

Význam tématu

Portable Raman spectroscopy capable of penetrating opaque barriers meets critical needs across security, pharmaceutical, cultural heritage and research sectors. By enabling non-destructive identification of substances inside sealed containers, this approach preserves sample integrity and enhances operator safety. Strong signal recovery below diffusive layers expands analytical reach into logistics screening, forensic casework and on-site material characterization.

Cíle a přehled studie / článku

This application note presents the design and performance of a portable Raman analyzer (STRam®) optimized for through-package detection. Key goals include enhancing subsurface signal collection, maintaining low optical power density, integrating high-sensitivity detection, and providing flexible software support. The system is demonstrated on a range of barrier types including plastic, paper and multi-layer packaging.

Použitá metodika a instrumentace

The methodology combines specialized laser excitation, large-spot sampling optics and advanced signal processing:

• Laser module: 785 nm or 1064 nm excitation, up to 420 mW output with 1 % power adjustment.
• Spectrometer variants: BWS475-785H-ST (150–2800 cm⁻¹, <6 cm⁻¹ resolution at 912 nm) or BWS475-1064-ST (100–2500 cm⁻¹, <10 cm⁻¹ at 1296 nm).
• Detectors: high-quantum-efficiency CCD at 785 nm or InGaAs array at 1064 nm, cooled to –25 °C/–20 °C.
• Sampling optics: fiber-optic see-through probe with large spot size, optional focus adaptors and immersion lenses.
• Electronics and software: tablet-mounted, 21 CFR Part 11 compliant BWID®-Pharma for STID algorithms; BWSpec® for laboratory control; BWIQ® for chemometric modeling (PLS, PCA, SVM).
• Power and portability: AC adaptor or optional battery, housed in a 40×26×25 cm enclosure weighing ~8.8 kg.

Hlavní výsledky a diskuse

System evaluation demonstrates reliable identification of hidden materials in plastic bottles, paper bags and logistics packages without container opening. Large sampling area reduces variability in heterogeneous samples; low power density avoids thermal or photochemical damage. Advanced STID algorithms effectively extract subsurface Raman signatures, outperforming conventional focused probes. The integrated tablet interface streamlines workflows and ensures data integrity under regulatory requirements.

Přínosy a praktické využití metody

The portable Raman solution offers:

• Non-invasive screening of pharmaceuticals, narcotics and explosives.
• Rapid customs and logistics inspections for concealed contraband.
• On-site archaeological pigment and mineral analysis without sampling.
• Forensic casework to identify substances without altering evidence.
• Flexible research platform for materials science and biosciences.

Budoucí trendy a možnosti využití

Emerging directions include integration with artificial intelligence for automated spectral interpretation, miniaturized multi-modal probes combining Raman with IR or fluorescence, and extended wavelength excitation to target challenging matrices. Cloud-based data libraries and real-time collaborative platforms will further enhance field deployments.

Závěr

The STRam portable Raman analyzer represents a versatile, high-sensitivity tool for through-barrier material identification. Its combination of optimized optics, advanced detection and compliance-ready software delivers rapid, non-destructive analysis across diverse application domains, reducing the need for container opening and improving operator safety.

Reference

• B&W Tek, LLC. STRam® Portable Raman Analyzer Application Note, Doc-Rev: 280001279-G, 2020.