Aim: To obtain IR spectra of know solid sample and liquid sample using the following sample preparing technique: Prepare solid IR sample using Solid Pellet Samplin Technique Use
IR is used to identify functional groups.
5 major functional groups easily identified by IR spectroscopy: 1.
C=O 2. C–O 3. OH 4. Phenols 5. C–H
Type of spectrophotometer: Nicolet 380 FT-IR spectroscopy, Nicolet Avatar 360 & Thermo Scientific iS10 FT-IR Spectrometer Type of radiation source:
Methods of Sample Preperation
Initially the plates were rinsed with ethanol, then dried with lint0free tissues. Next 1-2 g of benzoic acid were transferred to a mortar and a pestle was then use to grind the sample. About 100-150 mg of oven dried potassium bromide were added into the mortar and mixed well and then grinded. Next a screw was attached to a bolt and tightened together to make a sample holder. Next another screw was attached to the bolt to fasten it. The sample holder was then mounted onto the sample holder support on the table bench and a wrench was used to tighten the screw. It was held there for about 1-2 minutes and the bolts were loosened and removed. It was made sure not to fasten the bolts too tight or it would damage the bolt and the screw sample holder. After removing the two screws and transparent solid sample pellet ready to be measured was found formed within the screw. The advantages and disadvantages of different methods
The advantage of different methods is that you can see the different IR spectrums. The disadvantage is that you may get different results due to the different samples. Procedure for running IR
#Describe in detail the method(s) used for the preparation of your samples The sample needs to be dried in the desiccators before running IR because these neat samples allow no production of extraneous absorptions to obscure the spectra. The FT-IR spectroscopy was first allowed to warm up for at least...
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