Understanding Resolution in FTIR Spectroscopy

In summary, the conversation discusses the concept of resolution in FTIR spectroscopy and its impact on analyzing molecular structures. The resolution setting of the instrument determines its ability to resolve peaks in a sample, with a higher resolution setting providing more accurate and detailed results. It is suggested to try different resolution settings to determine the best one for a particular sample. A change in 2cm-1 may not be significant enough to indicate a change in molecular structure, but a change of 0.5ev (~4000cm-1) could be more meaningful.
  • #1
umalaya
2
0
Hi,

Can anyone help to explain the term of resolution in FTIR spectrocopy machine and...

1) If a sample A show a band centered 1650cm-1 and after some modify, the sample A show a band centered at 1652cm-1, can we consider the sample change in its molecular structure because it has a band shifted (if we have a resolution setting at 4 cm-1) ?

2) is it the resolution setting of 1cm-1 is always better than the resolution of 4cm-1, 8cm-1 and etc...

Thank you very much...
 
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  • #2
Hi,
After some modify ? what does that mean. Did you modify the sample or instrument?
Resolution: It is the ability of the instrument to resolve peaks.
For you second question, i would say 1 cm-1 is better than 4 or 5 or 6 cm-1. But off course it depends on lots of factor.
 
  • #3
Hi,

Thank you. Ya, I mean modify the sample.





Rajini said:
Hi,
After some modify ? what does that mean. Did you modify the sample or instrument?
Resolution: It is the ability of the instrument to resolve peaks.
For you second question, i would say 1 cm-1 is better than 4 or 5 or 6 cm-1. But off course it depends on lots of factor.
 
  • #4
I think then in your case the slight change (2 cm-1) is not encouraging..because it is less than the resolution of your instrument..
May be you can try using high resolution. It is up to you to decide.
good luck
 
  • #5
in ftir systems resolution is associated with the distance that the moving mirror travels i.e. a resolution of 2cm-1 means mirror moves 0.5cm from its natural focal focal point called ZPD. Longer the distance traveled by the moving mirror, more sharp features on the sample are explorable. But as it is already explained it depends on your sample and also time you have to perform experiment. Good practice is that you perform experiment at different resolutions and see if there are any fine structures in your sample. If not then stick to the resolution which gives results in less time.
A change in 2cm-1 is too less to deduct any thing, probably something in your sample has changed but not the molecular structue but some impurity. A change of 0.5ev(~4000cm-1) may mean something.
 

Related to Understanding Resolution in FTIR Spectroscopy

1. What is resolution in FTIR spectroscopy?

Resolution in FTIR spectroscopy refers to the ability to distinguish between two closely spaced peaks in an infrared spectrum. It is a measure of the instrument's ability to separate and identify spectral features, and is usually expressed in terms of wavenumber or wavelength difference between the two peaks.

2. How is resolution determined in FTIR spectroscopy?

Resolution is determined by the width of the spectral peaks in an infrared spectrum. The narrower the peaks, the higher the resolution. This can be achieved by using a higher quality instrument, such as one with a longer pathlength or higher signal-to-noise ratio, or by using advanced data processing techniques.

3. Why is resolution important in FTIR spectroscopy?

Resolution is important because it affects the accuracy and precision of measurements made using FTIR spectroscopy. Higher resolution allows for better identification and quantification of spectral features, and can also reveal more subtle changes in a sample's chemical composition.

4. What factors can affect resolution in FTIR spectroscopy?

The main factors that can affect resolution in FTIR spectroscopy include the quality of the instrument, the type of sample being analyzed, the concentration of the sample, and the data processing techniques used. Other factors such as temperature, pressure, and instrument alignment can also have an impact on resolution.

5. Can resolution be improved in FTIR spectroscopy?

Yes, resolution can be improved in several ways, such as using a higher quality instrument, optimizing the sample preparation and measurement conditions, and employing advanced data processing techniques. It is important to note that resolution is limited by the instrument's inherent capabilities, so it may not be possible to improve it beyond a certain point.

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