Question: How Does ATR IR Work?

What is ATR in infrared spectroscopy?

Attenuated total reflection (ATR) is a sampling technique used alongside traditional infrared spectroscopy, which ultimately qualifies samples to be observed directly in an either solid or liquid state, without additional preparation..

What are the advantages of ATR FTIR as compared to other sample introduction methods?

One of the key advantages of ATR-FTIR imaging is that it requires minimal or no sample preparation prior to spectral measurements. This is due to the fact that the penetration depth of IR light in the sample for ATR measurements is independent of sample thickness.

Why is KBr used in IR?

Potassium bromide (KBr, spectroscopic grade) is typically used as the window material because it is transparent in the IR, between 4000–400 cm-1. Alternatively, samples can be contained within a KBr matrix and pressed to form a pellet that is then analysed.

Why is KBr IR inactive?

The KBr does not show any absorption spectrum in IR region because it has a 100% transmission window in the range of wave number (4000-400 cm-1) at the FTIR spectroscopy with electronegativity of 2.0 based on the Pauling scale.

What is the main advantage of the ATR method?

As mentioned, the major benefit of ATR is the ability to measure a wide variety of solid and liquid samples without requiring complex preparations. The basic principle is shown in Figure 2. The ATR crystal comprises an IR transparent material with a high refractive index and polished surfaces as shown in Figure 2.

What is the difference between ATR and FTIR?

Attenuated total reflectance (ATR) is a special accessory unit which can be used with Fourier transform infrared (FTIR) spectrometers. … The ATR-FTIR technique makes it possible to study materials which are non-transparent to infrared radiation in a pristine condition.