ATR Sampling Accessories for the Agilent Cary 630 FTIR Spectrometer

Importance of ATR Sampling in FTIR Spectroscopy

Attenuated total reflectance sampling has become a standard approach in FTIR spectroscopy due to its rapid and versatile handling of diverse materials. By generating an evanescent wave at the crystal sample interface, ATR enables nondestructive analysis of liquids, solids, pastes and powders with minimal sample preparation.

Objectives and Study Overview

This overview examines the ATR sampling modules designed for the Agilent Cary 630 FTIR spectrometer. It outlines the principle of operation for single and multireflection ATR sensors and compares the performance of zinc selenide, diamond and germanium elements. Across multiple application examples, it demonstrates how these modules address analytical challenges in quality control, research and industrial workflows.

Methodology

Infrared radiation is directed through an ATR crystal where it is internally reflected. One or multiple reflections generate an evanescent wave that penetrates a thin layer of sample. The penetration depth depends on the refractive index of the sensor material and the sample. Sample contact is achieved with a swivel press for single reflection sensors while multireflection modules rely on multiple internal bounces.

Instrumentation

The Agilent Cary 630 FTIR spectrometer features a modular front end for instantaneous exchange of ATR sensors without realignment. The available modules include

• Single reflection ZnSe for a broad spectral range and moderate sensitivity suitable for soft solids, pastes, gels and liquids
• Multireflection ZnSe for extended pathlengths and enhanced sensitivity in dilute liquid and paste analysis
• Single reflection diamond for durable performance with hard solids, extreme pH solutions and abrasive samples
• Single reflection germanium for shallow penetration in highly absorbing or scattering materials such as carbon black filled polymers

Measurement routines are streamlined using Agilent MicroLab software for guided workflows, cleaning prompts and spectral identification.

Key Results and Discussion

Each ATR sensor delivers class-leading performance when paired with the Cary 630 FTIR custom optics:

• ZnSe modules provide reliable spectra of gels, liquids and soft solids
• Diamond ATR excels with abrasive materials and extreme pH environments
• Ge ATR offers selective analysis of highly absorbing samples with minimal background

Real-world applications demonstrate strong correlation with reference techniques:

• Sucrose quantification in infant cereals compared to HPLC
• Identification and purity testing of pharmaceutical ingredients
• Cannabinoid potency screening in cannabis extracts
• Fuel blend composition using multireflection ZnSe
• Alcohol level determination in hand sanitizers
• Prescreening of seized cocaine samples via automated spectral matching

Benefits and Practical Applications

The Cary 630 FTIR ATR system offers

• Rapid sensor exchange with no optical alignment
• Broad material compatibility and minimal sample preparation
• High sensitivity options for dilute or weakly absorbing samples
• Robust design resistant to acids, bases and mechanical wear
• Guided software workflows for routine quality control

Future Trends and Application Opportunities

Future developments aim to integrate ATR FTIR systems with inline process monitoring and artificial intelligence for real-time spectral interpretation. Miniaturization and enhanced sensor materials could expand applications in field analysis, environmental monitoring and pharmaceutical manufacturing. Advances in software algorithms will further improve quantitative accuracy and automated decision making.

Conclusion

The Agilent Cary 630 FTIR with its modular ATR accessories provides a flexible high-performance solution for a wide range of analytical challenges. Custom-engineered sampling modules deliver sensitivity, durability and ease of use, enabling rapid routine measurements across industries.