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What is meant by Attenuated Total Reflectance?

Attenuated total reflection (ATR) is a sampling technique used in conjunction with infrared spectroscopy which enables samples to be examined directly in the solid or liquid state without further preparation.

What is meant by Attenuated Total Reflectance?

Attenuated total reflection (ATR) is a sampling technique used in conjunction with infrared spectroscopy which enables samples to be examined directly in the solid or liquid state without further preparation.

How does Attenuated Total Reflectance work?

How does it work? An ATR accessory operates by measuring the changes that occur in an internally reflected IR beam when the beam comes into contact with a sample. An IR beam is directed onto an optically dense crystal with a high refractive index at a certain angle.

What is ATR technique?

1 Attenuated Total Reflectance (ATR) ATR is a contact sampling method that involves a crystal with a high refractive index and excellent IR transmitting properties. ATR is one of the more popular sampling techniques used by FT-IR Spectroscopists because it is quick, non-destructive and requires no sample preparation.

What is the difference between ATR and FTIR?

All Answers (15) FTIR is any Fourier Transform Infrared spectroscopy method in any measuring geometry, may it be transmission, reflection or whatever. ATR stands for attenuated total reflection and is developed in order to enhance the surface sensitivity since IR spectroscopy is a bulk method.

Why do we use ATR in FTIR?

ATR-FTIR spectra provide information on functional groups near the surface (~ 1 μm) of an internal reflection element (IRE). A key advantage to ATR-FTIR relative to other FTIR collection methods, and analytic techniques in general, is the ability to collect accurate spectra of samples in the presence of water.

Why ATR is used in FTIR?

ATR works well for these samples because the intensity of the evanescent waves decays exponentially with distance from the surface of the ATR crystal, making the technique generally insensitive to sample thickness.

Why is ATR better than FTIR?

When interpreting ATR-FTIR spectra where quantitative results are important, note that non-corrected ATR spectra have much stronger absorbance bands at longer wavelengths (smaller wave numbers) than at shorter wavelengths (larger wave numbers) compared to normal FTIR transmittance spectra.

How much does an FTIR cost?

For routine analysis, the price of an FTIR ranges from $15,000 to $20,000.

Why is KBr IR inactive?

KBr is used as a carrier for the sample in IR spectrum and it is optically transparent for the light in the range of IR measurement. So that no interference in absorbence would occur. KBr, has a transmittance of 100 % in the range of wave number (4000-400 cm-1). Therefore, it does not exhibit absorption in this range .

Why is KBr used in IR spectroscopy?

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.

Can ATR analyze toxic materials?

-ATR can be used to analyze toxic materials.