ZINC SELENIDE ATR ACCESSORY FOR THE AGILENT CARY 630 FTIR

Significance of Topic

The zinc selenide (ZnSe) attenuated total reflectance (ATR) accessory represents a critical advancement in infrared spectroscopy workflows. By eliminating extensive sample preparation and enhancing spectral quality, this accessory addresses the growing demand for rapid, reliable analysis of solids, liquids, and gels across research, quality control, and field environments.

Study Objectives and Overview

This application note details the design, integration, and performance of the Agilent ZnSe ATR accessory when coupled to the Cary 630 FTIR system. Key goals include demonstrating increased energy throughput, improved sensitivity at low analyte concentrations, and user-friendly operation without the need for alignment.

Methodology and Instrumentation

Setup and Components

• Agilent Cary 630 FTIR spectrometer featuring a rugged, mobile-designed interferometer.
• Single-bounce ZnSe crystal ATR accessory with a 45° incident angle.
• Built-in pressure clamp and slip clutch for consistent sample contact.
• Software interface offering guided workflows, multi-language support, status alerts, and cleaning reminders.

Operating parameters

• Mid-infrared measurement range: 5100–600 cm⁻¹.
• Effective penetration depths: 1.1 µm at 4000 cm⁻¹; 2.6 µm at 1700 cm⁻¹; 7.3 µm at 600 cm⁻¹.
• Rapid accessory changeover (< 10 seconds) without realignment.

Main Findings and Discussion

Compared to conventional multi-reflection ATR and transmission cells, the ZnSe ATR accessory delivered higher energy throughput and lower noise levels. This resulted in:

• Enhanced sensitivity and quantitation limits for common sample matrices.
• Complete mid-IR spectral coverage enabled by the wide ZnSe transmission window.
• Robust performance under humid and tropical conditions, confirming environmental stability.

Benefits and Practical Applications

Key advantages of the ZnSe ATR accessory include:

• Ease of use: snap-in design, no optical alignment, built-in pressure control.
• Versatility: direct analysis of solids, liquids, pastes, and gels without preparation.
• Speed: real-time data collection and immediate software-guided interpretation.
• Compactness: minimal bench footprint (9.2 × 8.9 cm) and low weight (0.9 kg).

Practical applications span polymer identification, pharmaceutical QC, environmental monitoring, and field-based material verification.

Future Trends and Potential Applications

Emerging directions include integration with variable pathlength accessories (DialPath, TumblIR) for broader concentration ranges, development of novel ATR crystal materials for extended spectral limits, and coupling with machine learning algorithms for automated spectral interpretation. Portable FTIR platforms promise expanded on-site analysis in industrial and environmental settings.

Conclusion

The Agilent ZnSe ATR accessory paired with the Cary 630 FTIR delivers superior sensitivity, rapid operation, and robust performance, making it a preferred choice for laboratories and field applications requiring high-quality infrared data without complex sample preparation.

References

• Agilent Technologies, Inc. 2016. Zinc Selenide ATR Accessory for the Agilent Cary 630 FTIR. Publication 5991-6930EN.