FT-IR Microscopic Analysis of Micro-particles

Importance of the Topic

The analysis of micro-particles is critical in fields such as pharmaceuticals, electronics, environmental monitoring and material formulation. FT-IR microscopy enables the chemical characterization of individual particles with micrometer resolution, offering a non-destructive approach that surpasses most bulk analytical techniques.

Objectives and Overview of the Study

This application note demonstrates the capabilities of the LUMOS II II FT-IR microscope through two case studies: the identification of particulate contaminants in a pharmaceutical formulation and the analysis of a defect inclusion in a multilayer acrylic varnish.

Methodology and Instrumentation

• The LUMOS II II is a standalone FT-IR microscope featuring an integrated spectrometer and fully motorized optics, including an 8× objective to support ATR, transmission and reflection modes.
• A motorized ATR crystal and automated stage enable unattended background and sample measurements as well as chemical imaging in various modes.
• OPUS Video-wizard software guides users through each measurement step, combining ease of use for routine applications with sensitivity suitable for demanding analyses.

Main Results and Discussion

• Pharmaceutical contaminant analysis involved filtering a sample through a 5 µm gold filter, performing ATR measurements at three distinct locations. Library searches identified cellulose, talcum and a talcum–amide polymer mixture, facilitating source tracking of impurities.
• In the varnish inclusion study, a ~22 µm defect was mapped using a 7×7 grid with 12×12 µm apertures. Chemical imaging based on characteristic amide bands highlighted the inclusion, and library matching confirmed its polyamide composition.

Benefits and Practical Applications of the Method

• Single-particle chemical identification with micrometer spatial resolution.
• Non-destructive workflow allows subsequent analytical techniques.
• Automated procedures streamline routine quality control and research.
• Chemical imaging visualizes particle distributions across larger areas for comprehensive assessment.

Future Trends and Applications

Anticipated developments include integration of AI-driven spectral interpretation, higher-throughput automated mapping, and expanded use in pharmaceutical QA/QC, environmental monitoring and advanced material characterization.

Conclusion

The LUMOS II II FT-IR microscope combines high sensitivity, automation and versatile measurement modes to deliver efficient, reliable chemical analysis of micro-particles, supporting both routine and complex analytical tasks.

References

• Bruker Optics. Application Note AN M105: FT-IR Microscopic Analysis of Micro-particles (2021).