ATR Sampling Accessories for the Agilent Cary 630 FTIR Spectrometer

Significance of the Topic

Attenuated total reflectance (ATR) is a cornerstone technique in infrared spectroscopy, enabling rapid, non-destructive analysis of a wide array of samples, from liquids and gels to powders and robust solids. Its versatility and minimal sample preparation streamline workflows in research, quality control and industrial settings, making ATR-FTIR indispensable for modern analytical laboratories.

Aims and Study Overview

This study presents a comprehensive technical overview of ATR sampling accessories designed for the Agilent Cary 630 FTIR spectrometer. It aims to guide users on selecting the optimal ATR sensor for specific sample types, explain the underlying principles of ATR measurements and highlight practical application examples across various industries.

Methodology and Instrumentation

The report explains the ATR measurement principle, in which an evanescent wave penetrates the sample at the crystal interface upon internal reflection. Four custom-engineered ATR modules are described:

• Single reflection zinc selenide (ZnSe): optimal for pliable solids, pastes, gels and liquids within pH 5–9.
• Multireflection ZnSe: extended pathlength for enhanced sensitivity in dilute solutions, pastes and non-viscous liquids.
• Single reflection diamond (Di): high durability sensor for hard solids, abrasive materials and extreme pH conditions.
• Single reflection germanium (Ge): shallow penetration depth, ideal for strongly absorbing or scattering samples such as carbon-black polymers.

Each sensor effortlessly mounts on the Cary 630 FTIR via a no-alignment design, and single-reflection modules feature a swivel press for reproducible sample contact.

Main Results and Discussion

Custom-matched modules deliver class-leading sensitivity and ease-of-use. Single-reflection sensors provide high throughput for concentrated samples, while the multireflection ZnSe module achieves lower detection limits. Practical examples demonstrate:

• Quantitative sucrose analysis in infant cereals, correlating well with HPLC.
• Authentication and counterfeit screening of pharmaceuticals, including ethambutol and cefuroxime.
• Rapid THC potency screening in cannabis extracts without sample preparation.
• Differentiation of alcohol content in hand sanitizers via automated QC routines.
• Fuel-blend composition analysis in diesel/butanol mixtures.
• Prescreening of seized cocaine samples to identify illicit substances non-destructively.

Benefits and Practical Applications

The modular ATR platform simplifies method development, reducing analysis time and operator intervention. It supports a broad range of sample forms and concentrations, enabling reliable QA/QC in pharmaceuticals, food, energy and forensic laboratories. The diamond sensor’s robustness and Ge’s shallow penetration deliver unique capabilities for challenging materials.

Future Trends and Opportunities

Anticipated developments include miniature ATR probes for in situ process monitoring, integration with automated sampling robots and advanced chemometric algorithms for real-time data analysis. Emerging crystal materials may further extend spectral ranges and enhance sensitivity.

Conclusion

The Agilent Cary 630 FTIR’s suite of custom-engineered ATR modules offers unmatched flexibility, performance and simplicity. By selecting the appropriate sensor material and configuration, analysts can achieve reliable, rapid and sensitive infrared measurements across diverse application areas.

Used Instrumentation

• Agilent Cary 630 FTIR spectrometer (KBr or ZnSe optics)
• Single reflection ATR modules: ZnSe, diamond, Ge (swivel press)
• Multireflection ZnSe ATR module