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FT-IR Spectroscopy

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    CHEM341. Instrumental Analysis

    In-Class Exercise

    Exercise – Camphor and FT-IR parameters

    1. Previously, I collected camphor’s FT-IR spectrum using the ATR accessory under a variety of settings.

      The first spectrum was collected using the parameters values below:

      Number of scans:  ___1___

      Resolution (cm-1):  ___1___

      Optical speed (cm/s):  ___0.4747___

      Apodization function: ___Happ-Genzel____

       

    1. What happens when we change the resolution from 1 to 4 to 32 (all other parameters stay the same)?





       
    2. What happens when we change the number of scans from 1 to 4 to 32 (all other parameters stay the same)?




       
    3. Why would we also have to rerun the background spectrum after changing parameters?




       
    4. How do the following settings impact FT-IR spectra?

      Number of scans:



       

      Resolution (cm-1):



       

      Apodization function:




       

    5. What factors determine the time required to collect FT-IR spectra?




       

    Now, we’ll look at the interferogram (e.g., the raw data!)

    1. What do the interferogram axes represent?




       
    2. How do the number of data points in the interferogram change as resolution increases?







       

    Contributors and Attributions

    This page titled FT-IR Spectroscopy is shared under a CC BY-NC-SA 4.0 license and was authored, remixed, and/or curated by David Griffith via source content that was edited to the style and standards of the LibreTexts platform; a detailed edit history is available upon request.