Shelby Bleile
Lab 5: IR, Raman, & IR Microscopy Lab
Introduction:
FTIR stands for Fourier Transformed Infrared Spectroscopy. From this
instrument you can determine what functional groups are in an analyte. It does this by
looking at the bond types and the corresponding wave numbers. It is most commonly
used for qualitative analysis. The Raman can analyze samples containing water, where
the FTIR can only analyze organic solvents. IR microscopy is useful is analyzing fibers
such as in different fabrics.
Purpose:
The purpose of this lab is to learn how to use to the IR by running different
organic solvents and to learn how to use the IR microscope by comparing fibers. The
week we did this lab, the Raman was down.
Procedure:
IR:
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Investigate operation by running samples of three organic solvents
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Run different mixtures of these solvents
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Create a calibration curve
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Run an unknown mixture and determine concentration of each component
IR Microscope:
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Learn how to operate IR in microscopy mode
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Obtain a good spectra for known fibers
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Run unknown fibers and compare
Results:
-FTIR
We ran different organic solvents mixtures, which included Toluene, 2 Propanol, and 2
Butanol in different parts as well as unknowns.
Figure 1: Sample of 2-Butanone absorbance spectrum
Figure 2: 2 – butanone % transmittance
Figure 3: 2-propanol absorbance spectrum.
Figure 4: 2-propanol % transmittance.
Figure 5: Toluene absorbance spectrum
Figure 6: Toluene % transmittance
Figure 7: Mix 1 absorbance spectrum
Figure 8: Mix 1 % transmittance
Figure 9: Mix 2 absorbance spectrum
Figure 10: Mix 2 % transmittance
Figure 11: Mix 3 absorbance spectrum
Figure 12: Mix 3 % transmittance
Figure 13: Mix 4 Absorbance spectrum
Figure 14: Mix 4 % transmittance
Figure 15: Unknown sample absorbance spectrum
Figure 16: Unknown sample % transmittance
FTIR Microscope
We ran different samples of fibers on the instrument.
Figure 17: Sample of Cotton
Figure 18: Cotton (80%) Polyester (20%)
Figure 19: Nylon (85%), Elastane (15%)
Figure 20: Polyester (70%), Acrylic (30%)
Figure 21: Polyester (50%), Cotton (50%)
Figure 22: Unknown sample of fibers. Looked similar to a polyester cotton mix.
Conclusion:
We were able to easily run these instruments after some initial help with the lab
assistants. We were able to obtain good spectrums from the FTIR and the IR
microscope. The runs were very quick, which I know is due to the fact that the IR uses
an interferometer. This allows the IR to quickly scan the sample through all the
spectrum and allows it to be precise.