FTIR talk letter (Vol. 43)

Importance of the Topic

The development of advanced tools and methodologies for infrared spectral analysis and microplastic evaluation addresses key challenges in analytical chemistry. Spectrum Advisor enhances the reliability of FTIR measurements for users of all experience levels. Detailed spectral interpretation of olefins and aromatics underpins polymer identification, while a comprehensive instrumentation lineup streamlines sample preparation and analysis of environmental microplastics.

Objectives and Overview

This summary integrates three core developments: the introduction of Shimadzu’s Spectrum Advisor feature for FTIR data quality control, practical notes on distinguishing aliphatic unsaturated hydrocarbons and aromatics by infrared spectroscopy, and a product line for microplastic analysis from sample pretreatment to component identification. It aims to highlight study goals, methodological advances, main findings, and their practical impact.

Methodology and Instrumentation

Key approaches and systems:

• Spectrum Advisor in LabSolutions IR version 2.33, supporting FTIRSpirit-X series for transmission, reflection and ATR measurements
• Interactive diagnosis workflow guiding users through measurement mode, spectral feature selection, and targeted solutions for noise, baseline drift, and sample handling issues
• Infrared analysis of polymers using characteristic peak assignments: C–H stretching (3 200–2 800 cm⁻¹), C=C stretching (1 700–1 450 cm⁻¹), and C=C–H out-of-plane bending (1 000–800 cm⁻¹)
• Correlation charts for olefin isomers, aromatic substitution patterns (670–900 cm⁻¹ and 1 660–2 000 cm⁻¹ regions), and butadiene rubber cis/trans content
• Microplastic workflow combining MAP-100 automatic pretreatment unit, Plastic Analyzer FTIR system, and AIMsight/AIRsight infrared/Raman microscopes

Main Results and Discussion

Spectrum Advisor enables analysts with limited FTIR experience to diagnose poor‐quality data by comparing user spectra with reference high-/low-quality examples and to apply corrective actions such as optimizing background measurement power and increasing scan numbers. In polymer analysis, clear spectral markers distinguish paraffins, olefins, and aromatics by peak positions above 3 000 cm⁻¹, around 1 650 cm⁻¹ vs. 1 600/1 500 cm⁻¹, and C=C–H bending bands indicative of isomeric forms or substitution patterns. For butadiene rubbers, the relative intensities of vinyl, trans-, and cis-vinylene peaks directly reflect material cis/trans content. Finally, Shimadzu’s microplastic platform integrates sample isolation, imaging, particle counting, and nondestructive component identification in a unified workflow.

Benefits and Practical Applications

• Enhanced data quality control for routine FTIR measurements without specialist intervention
• Rapid differentiation of polymer types and structural isomers in quality-control and research settings
• Quantitative assessment of structural isomers in elastomers, supporting material performance optimization
• Streamlined environmental analysis of microplastics, reducing manual handling and analysis time

Future Trends and Potential Applications

• Integration of AI-driven spectral interpretation to further automate identification of complex mixtures and functional groups
• Expansion of automatic pretreatment systems to handle diverse environmental and biological matrices
• Development of real-time monitoring solutions for microplastic contamination in water treatment and food safety
• Advanced correlation of infrared/Raman multimodal data for comprehensive polymer and microplastic characterization

Conclusion

Shimadzu’s Spectrum Advisor feature and targeted spectral analysis guidelines significantly lower barriers to high-quality FTIR data acquisition and polymer identification. Coupled with a dedicated microplastics analysis product line, these advances offer robust, user-friendly solutions for research, industrial, and environmental monitoring applications.

Used Instrumentation

• LabSolutions IR software version 2.33
• FTIRSpirit-X series Fourier transform infrared spectrometers
• IR Pilot analysis navigation program
• AMsolution for AIMsight and AIRsight infrared/Raman microscopes
• MAP-100 Microplastic Automatic Preparation Device
• Plastic Analyzer FTIR system

References

1. Xu Yan, Karen Maruyama, “FTIR Analysis of Recycled Plastics Using the Spectrum Advisor Function,” Shimadzu Application News 01-00653-EN (Dec. 2023)
2. Shigeyuki Tanaka and Norio Teramae, Infrared Spectroscopy, Kyoritsu Shuppan (1993)
3. N. B. Colthup, J. Opt. Soc. Am. 40, 397 (1950)
4. P. J. Larkin, Infrared and Raman Spectroscopy: Principles and Spectral Interpretation, Second Edition, Elsevier (2017)
5. Takuo Sone, Journal of the Society of Rubber Science and Technology, Japan, 88, 178 (2015)