ir-nmr-procedure

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Infrared (IR) Spectroscopy Procedure Photo: []

__ Preparing a Sample Using NaCl Plates __
 * 1) Obtain two samples (one known, one unknown)
 * 2) Record the identity of the known and the identification code of the unknown in your lab notebook
 * 3) Obtain two NaCl plates from the laboratory instructor. //Wear gloves while handling plates, touch only edges of plates.//
 * 4) Rinse plates thoroughly with dichloromethane using a pipet.
 * 5) Dry the plates using lint-free tissues
 * 6) Use a Pasteur pipet to place 1-2 drops of the known sample on one of the plates.
 * 7) Gently press the plates together to remove any air bubbles.
 * 8) Place the plates on the sample holder.
 * 9) Make certain there is nothing in the sample compartment of the IR spectrophotometer.
 * 10) Obtain a background spectrum.
 * 11) Place the sample holder in the sample compartment.
 * 12) Record an IR spectrum for the known sample.
 * 13) Check with your laboratory instructor to be sure that the spectrum is acceptable. //If the spectrum is not acceptable, prepare a new sample and repeat the procedure until an acceptable spectrum is obtained.//
 * 14) Repeat steps 3-13 using the unknown sample.
 * 15) Record the major bands in the unknown spectrum.
 * 16) Compare the unknown spectrum to the known spectra in the laboratory and standard IR spectra provided.
 * 17) Report the identity of the unknown compound.
 * 18) Clean up all waste and place in proper collection containers. Wash hands thoroughly with soap before leaving the laboratory.

1. Obtain a known sample and an unknown sample from your instructor. 2. Record the identity of the known sample and the number of the unknown sample in your lab notebook. 3. Prepare all the samples in the fume hood. 4. Place one drop of the known compound into the NMR tube. 5. Be sure to wear gloves and hold the tube at the very top. 6. Using a pasteur pipette, place 0.5 ml // d- // chloroform with 2-5 % tetramethylsilane (TMS) into the NMR tube. 7. Place the cap on the tube and mix thoroughly. 8. Wipe the NMR tube with a Kim wipe. 9. Place the NMR tube into the chamber and be sure that it is spinning. 10. Follow the instructions to operate the spectrometer. 11. Plot the spectrum. 12. Check with your laboratory instructor to see if the spectrum obtained is acceptable; obtain another spectrum if it is not acceptable. 13. Use the NUTS software to further analyze the spectrum. 14. Repeat steps 4-13 for the unknown compound. 15. Dispose of all materials in the appropriate containers and clean up area. 16. Wash hands thoroughly with soap and water.
 * Nuclear Magnetic Resonance (NMR) Procedure **