Metrohm i-Raman Pro portable Raman spectrometer

Significance of the Topic

The development of highly sensitive, portable Raman spectroscopy systems addresses the growing need for on-site, real-time chemical analysis in fields such as pharmaceuticals, forensics, environmental monitoring and cultural heritage conservation. By combining fiber-optic sampling with deep-cooled detectors and user-friendly interfaces, modern handheld Raman instruments empower scientists and technicians to perform high-precision qualitative and quantitative measurements outside the conventional laboratory setting.

Objectives and Overview of the Article

This article reviews the design and performance of the i-Raman Pro system, a battery-enabled, fiber-optic Raman spectrometer featuring a built-in touchscreen computer. It aims to illustrate how the combination of deep-cooled CCD detection, broad spectral coverage, high resolution and integrated software enhances analytical capabilities both in the lab and in the field.

Methodology

The system employs fiber-optic sampling probes coupled to a high-quantum-efficiency CCD detector maintained at –25 °C to minimize noise during long integration times. Two excitation lasers (532 nm and 785 nm) are available, each with adjustable power output. The embedded tablet runs touch-friendly software to control data acquisition and processing. A selection of optical accessories, including video microscope lenses for stand-off measurements, extends the flexibility of sampling various sample types and geometries.

Used Instrumentation

• Excitation sources: 532 nm (35–42 mW) and 785 nm (340–455 mW) lasers with 0–100% power control in 1% increments
• Spectral range: 65–4200 cm⁻¹ (model-dependent, down to 65 cm⁻¹) with resolutions from <4.5 cm⁻¹ to <3.5 cm⁻¹ (ASTM E2529-06)
• Detector: high-efficiency CCD array cooled to –25 °C, integration times from 7 ms to 30 min
• Electronics and interface: USB 2.0, trigger capability, AC (100–240 VAC) and optional battery power
• Software platforms: BWSpec for acquisition and real-time analysis; BWID for library-based identification and FDA-compliant workflows; BWIQ for multivariate chemometrics (PLS, PCA, SVM)
• Accessories included: fiber-optic probe, trigger cable, safety goggles, carrying case; optional: cuvette and probe holders, long-working-distance lenses, video microscope, immersion probes, flow cell, performance test kit

Key Results and Discussion

The i-Raman Pro demonstrates excellent signal-to-noise ratios during extended integrations, enabling detection of weak Raman signals in complex matrices. Its broad wavelength coverage allows characterization of molecular vibrations from the fingerprint region up to 4200 cm⁻¹. The deep‐cooled CCD and high dynamic range facilitate quantitative analyses with low detection limits. Integrated touchscreen control and modular software streamline workflows from data acquisition to chemometric modeling.

Benefits and Practical Applications

• On-site qualitative identification and quantitative analysis without laboratory infrastructure
• High spectral resolution and sensitivity for trace-level detection and complex sample matrices
• Flexible sampling across solids, liquids, powders and surfaces using interchangeable probes and lenses
• Regulatory compliance support through dedicated FDA 21 CFR Part 11 software
• Real-time process monitoring (PAT), forensic screening, pharmaceutical quality control and cultural heritage research

Future Trends and Potential Applications

Advances in detector technology, miniaturized laser sources and AI-driven chemometrics will further enhance portable Raman performance. Integration with cloud-based spectral libraries, machine learning for automated interpretation and expanded use in process analytical technology, biomedical diagnostics and environmental sensing are poised to broaden the impact of handheld Raman platforms.

Conclusion

The i-Raman Pro combines deep‐cooled CCD detection, broad spectral range, high resolution and an integrated touchscreen interface to deliver research-grade Raman spectroscopy in a portable package. Its versatile accessories and comprehensive software suite make it a powerful tool for on-site chemical analysis across diverse applications.

Reference

• B&W Tek, i-Raman Pro Product Datasheet, Doc-Rev: 280001260-J (2020)