Metrohm i-Raman Pro portable Raman spectrometer

Importance of the Topic

Raman spectroscopy is a pivotal analytical technique offering nondestructive identification and quantitation of chemical species across numerous fields. Portable, high-sensitivity instruments enable on-site measurements in areas ranging from pharmaceutical quality control and process monitoring to forensic science and cultural heritage studies. The ability to perform real-time analysis with minimal sample preparation enhances decision making in field operations and regulated environments.

Study Objectives and Overview

This document presents a comprehensive description of a portable, deep-cooled Raman spectrometer system designed for high sensitivity, wide spectral coverage, and user-friendly operation. Key aims include demonstrating the instrument’s performance parameters, outlining its software capabilities for identification and chemometric analysis, and showcasing its adaptability via sampling accessories for diverse applications in both laboratory and field settings.

Methodology and Used Instrumentation

The core of the system is a high-quantum-efficiency CCD array detector maintained at -25 °C to achieve low noise and high dynamic range. Excitation options include 532 nm lasers (35–42 mW) and 785 nm lasers (340–455 mW), with power adjustable in 1% increments. The spectral range spans 65 to 4200 cm⁻¹ with resolution down to 3.5 cm⁻¹ depending on the model. Sampling relies on a fiber-optic probe compatible with external triggers and allows measurements on solids, liquids, and powders.

Software packages support data acquisition, control, and analysis:

• BWSpec for instrument operation, real-time peak analysis, and data management.
• BWID for rapid material identification against spectral libraries, including 21 CFR Part 11 compliance in its Pharma edition.
• BWIQ for multivariate chemometric modeling (PLS, PCA, SVM) and real-time predictions.

A broad accessory set includes video microscope lenses for stand-off measurements, immersion probes, positioning stages, cuvette and flow-cell holders, and a wheeled carrying case with optional battery pack for extended field use.

Main Results and Discussion

The instrument delivers excellent signal-to-noise ratios for long integration tasks, maintaining stability across 0–35 °C ambient conditions. Models vary by excitation wavelength and spectral coverage, offering users trade-offs between resolution and spectral limit. Performance testing confirms Raman resolution per ASTM standards. The embedded tablet interface streamlines workflows and enables real-time quantitation and identification without external computers.

Key findings include:

• Mobile operation with battery power for true field portability.
• High sensitivity suitable for trace analysis and SERS applications.
• Flexible sampling configurations accommodating diverse sample geometries.

Benefits and Practical Applications

The combined features of deep cooling, touchscreen integration, and fiber-optic sampling make the system ideal for applications such as:

• Pharmaceutical raw material verification and process analytical technology (PAT).
• Forensic narcotics detection and crime-scene investigation.
• Art conservation, gemology, and geological research.
• Biomedical diagnostics and quality control in manufacturing.

Future Trends and Applications

Advancements are expected in areas including miniaturized detectors, enhanced chemometric algorithms driven by machine learning, and expanded SERS capabilities for ultra-trace analysis. Integration with cloud-based data platforms and automated PAT frameworks will further streamline remote monitoring. The development of ruggedized probes and extended wavelength excitation options will continue to broaden the versatility of portable Raman systems.

Conclusion

This portable, high-sensitivity Raman platform combines deep-cooled detection, flexible sampling, and powerful software tools to deliver research-grade performance in both lab and field environments. Its broad spectral range, high resolution, and real-time identification capabilities support a wide array of analytical challenges and position it as a valuable asset in modern analytical workflows.

References

1. B&W Tek, LLC. i-Raman Pro Deep-Cooled Portable Raman System. Doc-Rev: 280001260-J (2020/01/28).