IRIS Description:

The IRIS accessory is the go-to diamond ATR for every lab. It is designed to make IR sampling easy. You can expect high-quality spectra covering a wide range of samples from powders, gels, liquids, solids and more. It is ideal for research, QA/QC and sample identification. Data collection for most samples may be completed in less than one minute.

• High-performance diamond ATR

• Precision optics and design for high energy throughput

• Optional Ge ATR crystal for high refractive index samples

• Additional sampling tools – Flow-Through Attachment and Liquids Retainer

• Compatible with most FTIR instruments

The IRIS accessory is the go-to diamond ATR for every lab. It is designed to make IR sampling easy. You can expect high-quality spectra covering a wide range of samples from powders, gels, liquids, solids and more. It is ideal for research, QA/QC and sample identification. Data collection for most samples may be completed in less than one minute.

The backbone of the IRIS is its high-precision optics. IRIS’ powered mirrors have been designed and processed using diamond- turning technology to achieve optimal performance. All mirrors are gold-coated for maximum reflectivity.

The diamond ATR crystal, with a diameter of 1.8 mm, offers the ultimate sampling surface for most all samples. It provides extreme hardness, and is suitable for testing samples with pH values between 1-14. The unique PTFE seal for the diamond ATR element in the stainless-steel mounting plate adds to IRIS’ universal applicability for the analysis of a wide range of organic and caustic samples, due to inertness of PTFE. Other commercial ATR accessories rely on an epoxy seal, which may dissolve over continuous exposure to some organic solvents.

IRIS diamond ATR plate uses a small crystal to maximize the energy passing through the diamond phonon bands, inherent to all diamonds, and a strong metal brace on the underneath side to prevent microscopic movements of the ATR crystal. Together these two features allow the diamond phonon bands to ratio out in sample spectra resulting in the highest quality data. PIKE Technologies offers two diamond plates. Our anti-reflective Toluene spectrum collected using IRIS diamond ATR.

An uncoated diamond plate is also available to allow for measurements in the mid- and far-IR spectral regions. To offer the most flexibility, IRIS may also be fitted with a Ge ATR plate for measuring samples with a high refractive index. Types of samples that would benefit from using the Ge ATR crystal plate are carbon black filled samples and inorganic materials such as oxides, aluminas, titania and minerals. IRIS’ Ge element offers a wide transmission range spanning 4000 – 450 cm-1.

Single Reflection Attenuated Total Reflectance- A Guideline

Single Reflection Attenuated Total Reflectance (ATR) is a variation of the ATR spectroscopy technique, where only one internal reflection occurs at the interface between the ATR crystal or prism and the sample. In contrast, conventional ATR spectroscopy typically involves multiple internal reflections to enhance sensitivity and penetration depth. Single reflection ATR is also known as "single bounce ATR" or "single pass ATR."

In Single Reflection ATR, the incident infrared (IR) beam strikes the ATR crystal or prism at a specific angle, undergoes a single reflection at the interface with the sample, and then exits the crystal or prism to the detector. This setup simplifies the optical path and reduces the complexity of the spectroscopic system compared to multi-bounce ATR.

Key features and considerations of Single Reflection ATR include:

1. Simplified Optics: Single Reflection ATR setups have a simpler optical path, which can be advantageous in terms of alignment and maintenance.

2. Lower Signal-to-Noise Ratio: Compared to multi-bounce ATR, single reflection ATR may have a lower signal-to-noise ratio due to the reduced number of reflections. As a result, it might be less sensitive for certain applications.

3. Surface Sensitivity: Single Reflection ATR is more surface-sensitive compared to transmission-based techniques, as it primarily probes the molecular composition of the sample in contact with the ATR crystal or prism.

4. Limited Sampling Depth: The penetration depth of the infrared beam is shallower in single reflection ATR compared to multi-bounce ATR. This means that only the surface layers of the sample are probed, making it ideal for analyzing thin films, coatings, or surface contaminants.

5. Sample Types: Single Reflection ATR is particularly useful for analyzing samples that are difficult to prepare or handle, such as liquids, soft solids, and irregularly shaped samples.

6. Reproducibility: Single Reflection ATR may offer better reproducibility for certain samples compared to multi-bounce ATR due to the simplicity of the optical setup.

7. Time-Efficient: Single Reflection ATR typically requires less time for data acquisition compared to multi-bounce ATR.

Despite its advantages, Single Reflection ATR has limitations. The shallow sampling depth may not be suitable for samples with significant thickness or for the analysis of bulk properties. Additionally, the lower signal-to-noise ratio may require longer acquisition times or more sensitive detectors for certain applications.

The choice between single reflection and multi-bounce ATR depends on the specific requirements of the analysis, the nature of the sample, and the sensitivity needed. Researchers often select the ATR configuration that best suits their application and sample type to obtain accurate and reliable spectroscopic data.