Question: How To Take Infrared Spectrum?


  1. Turn on the IR spectrometer and allow it to warm up.
  2. Obtain an unknown sample from the instructor and record the letter and appearance of the sample.
  3. Collect a background spectrum.
  4. Using a metal spatula, place a small amount of sample under the probe.
  5. Twist the probe until it locks into place.

How is infrared spectrum measured?

The method or technique of infrared spectroscopy is conducted with an instrument called an infrared spectrometer (or spectrophotometer) which produces an infrared spectrum. An IR spectrum can be visualized in a graph of infrared light absorbance (or transmittance) on the vertical axis vs.

How do I prepare for a FTIR sample?

Add about 1 to 2 % of your sample, mix and grind to a fine powder. For very hard samples, add the sample first, grind, add KBr and then grind again. The sample must be very finely ground as in the Nujol mulling technique to reduce scattering losses and absorption band distortions.

Can you take an IR of a solid?

Briefly, the solid sample is dissolved in a suitable solvent (usually methylene chloride) and the solution is dropped onto a salt plate. After the solvent evaporates, a thin-solid film of the compound remains on the plate. The IR is run directly in the FT-IR.

You might be interested:  FAQ: What Uses Infrared Radiation?

What is IR used for?

Infrared (IR) spectroscopy is one of the most important and common spectroscopic techniques used by chemists for structural elucidation and compound identification [79]. IR spectroscopic analysis is used to determine the various chemical functional groups present in the sample.

How does an IR work?

Infrared (IR) spectroscopy uses infrared radiation to excite the molecules of a compound and generates an infrared spectrum of the energy absorbed by a molecule as a function of the frequency or wavelength of light. Different types of bonds respond to the IR radiation differently.

What is infrared used for?

Infrared sensing One of the most useful applications of the IR spectrum is in sensing and detection. All objects on Earth emit IR radiation in the form of heat. This can be detected by electronic sensors, such as those used in night vision goggles and infrared cameras.

What is mull technique?

a) Mull technique: In this technique, the finely crushed sample is mixed with Nujol (mulling agent) in n a marble or agate mortar, with a pestle to make a thick paste. A thin film is applied onto the salt plates. This is then mounted in a path of IR beam and the spectrum is recorded.

How do I do a FTIR analysis?

Testing Process

  1. Step 1: Place sample in FTIR spectrometer. The spectrometer directs beams of IR at the sample and measures how much of the beam and at which frequencies the sample absorbs the infrared light.
  2. Step 2: The reference database houses thousands of spectra, so samples can be identified.
You might be interested:  FAQ: Which Molecules Show Infrared Absorption Spectra?

What salt is used in IR sample prep?

Sodium chloride is chosen because it is transparent to infrared radiation. These plates – called “salt plates” – are rather expensive because each plate is cut from a single giant crystal; they are very fragile and sensitive to moisture, including the moisture in your fingers.

How do you dry KBr for IR?

Before forming the KBr powder into pellets, pulverize it to 200 mesh max. and then dry at approximately 110 °C for two to three hours. Note that rapid heating can oxidize some of the KBr powder to KBrO3, causing a brown discoloration. After drying the powder, store it in a desiccator.

Which source is used in IR spectroscopy?

The common radiation source for the IR spectrometer is an inert solid heated electrically to 1000 to 1800 °C. Three popular types of sources are Nernst glower (constructed of rare-earth oxides), Globar (constructed of silicon carbide), and Nichrome coil.

Leave a Reply

Your email address will not be published. Required fields are marked *

Back to Top