General Considerations

• IR optics are made from salt (KBr, NaCl, etc.) and are therefore very sensitive to moisture. Make sure not to leave the instrument open for any length of time. Salt plate sampling accessories should never be exposed to water or wet solvents (i.e., acetone, certain alcohols, etc.).
• The detector is cooled by liquid nitrogen. Make sure this is available before preparing your sample. Liquid Nitrogen is extremely COLD take appropriate precautions.
• For heaven's sake don't stick your head in the spectrometer in order to stare into the LASER beam.

Instructions

• Turn the computer on.
• Turn the infra-red (IR) instrument on. (back right switch)
  • If the lights on the instrument are green, this indicates that everything is ready to go.
• A flap located on the left side of the IR spectrometer. This is the location where liquid nitrogen must be poured into the IR's detector. After opening the flap, replace the inner plug with the plastic funnel. After filling, close the flap to insure that no moister gets into the machine. This will protect the optics since they are sensitive to moisture.
• The software application is opened by double clicking on "Omnic ESP." Username "cz".
• Upon opening this application, a dialogue box will appear. Click OK.
  • If the status is yellow, check to see that the bench aperture is set to 10. (found in Collect > Set-up > Bench tab or something like that)
• Start by collecting a background. Click on collect background to obtain a background spectrum. The background should always be just air (never include the cell).
• To collect a spectrum of the cell or sample click on collect sample.
• Turn the instrument off and power down the computer.

Spectral Analysis

• No spectra are saved unless you explicitly do so. (Use only the Chem450 folder).
• Selected spectra are colored red. Use the arrow cursor to click on a new spectrum to select it. Cntrl-click to select multiple spectra.
• Spectra can be hidden or cleared to reduce clutter. To select a hidden spectrum use the text description field.
• Zoom is accomplished by making a selection rectangle and clicking within it.
• Redisplaying the full spectrum is done by double clicking the white area of the mini-spectrum (bottom).
• cntrl-Z does an auto-Y-axis scaling.
• Two selected spectra can be subtracted from each other by selecting them both and clicking Process > Subtract. Alter the subtraction factor visually or numerically (by clicking on the factor button). A factor of 1.000 is usually most appropriate.
• Integration is done using the integration cursor (change cursors using the bottom left buttons). Use the cursor that has a baseline correction.