IR Calibration

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vgnarne
vgnarne's picture
IR Calibration

Hi Friends,
What is the Calibration parameters for FT-IR calibration, what are the references for FT-IR calibration?
Why we need to use Poly styrene film for calibrating FT-IR, What is the importance of 0.15 mm, 0.038 mm Polystyrine film for calibration
thank you,
vgnarne

Dr. Analytical
Dr. Analytical's picture
Calibration is more difficult

Calibration is more difficult in IR than with other analytical instruments.  First, like all instruments, you need a reference standard of known composition and purity.  However, the "path length" will affect the transmittance, so it must be known, or at least controlled.  This is easy to do with liquid solutions in a cell (much like UV absorbance spectrophotometry), but is much harder with a nujol mull, KBr pellet, or ATR crystal. You can try preparing solutions at different concentrations and attempt to measure the differences.
Can you provide more information on the polystyrene question?
 

vgnarne
vgnarne's picture
Dr. Analytical wrote:

Dr. Analytical wrote:

Calibration is more difficult in IR than with other analytical instruments.  First, like all instruments, you need a reference standard of known composition and purity.  However, the "path length" will affect the transmittance, so it must be known, or at least controlled.  This is easy to do with liquid solutions in a cell (much like UV absorbance spectrophotometry), but is much harder with a nujol mull, KBr pellet, or ATR crystal. You can try preparing solutions at different concentrations and attempt to measure the differences.
Can you provide more information on the polystyrene question?
 

At Present we are using polystyrene film for calibrating the parameters like Verification of wavenumber, resolutions at 1580 cm, 2500 cm why we need to use polystyrene film to calibrate FT-IR?, is there any other calibration procedures for calibrating FT-IR with ATR accesary?
 

Dr. Analytical
Dr. Analytical's picture
A polystyrene film is an easy

A polystyrene film is an easy way to calibrate the entire wavelength range of the instrument.  The film produces sharp absorbance bands at known wavelengths (or frequencies) which can be used to verify that the instrument's spectrum is accurate.  There are also some tests with this film related to absorbance of the bands, but this is not as common.
Most people are only using FTIR for identification, so wavelength accuracy is most important.  As I said earlier, if you want to do quantitative work, you must prepare your own calibration standards.
Thanks for posting your question at scientistsolutions.com.  Come back often.
 

dada
dada's picture
Why we need to use Poly

Why we need to use Poly styrene film for calibrating FT-IR, What is the importance of 0.15 mm, 0.038 mm Polystyrine film for calibration

 

PAVANKUMAR BONAGIRI
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I happy to join this group

I happy to join this group and also i am suggested answers in doubts and i  also gave the questions. ok..