What are salt plates used for in IR?

What are salt plates used for in IR?

What are salt plates used for in IR?

Salt plates are used to take an IR spectra of a liquid sample. The plates work the same way as the potassium bromide for solid samples. The major problem of using a liquid sample is choosing a solvent with which to dilute the sample.

Do salt plates absorb IR?

Infrared spectra may be obtained from samples in all phases (liquid, solid and gaseous). Liquids are usually examined as a thin film sandwiched between two polished salt plates (note that glass absorbs infrared radiation, whereas NaCl is transparent).

What is an IR plate?

IR-transparent salt plates are used to hold the sample in front of the beam in order to acquire data.

Which solvent should never be used to wash the salt plates used for IR?

NEVER use water (H2O) to clean a salt plate as it will ruin the plate, permanently!

Why is Nujol used in IR?

For very reactive samples, the layer of Nujol can provide a protective coating, preventing sample decomposition during acquisition of the IR spectrum.

Why are plates used for IR spectroscopy?

Because glass (i.e. quartz) would absorb in the IR spectrum, and mask the absorption of your sample.

Do NaCl plates used in IR absorb radiation in the infrared region?

How do you prepare an IR sample?

1) Making a sandwich To prepare a liquid sample to IR analysis, firstly place a drop of the liquid on the face of a highly polished salt plate (such as NaCl, AgCl or KBr), then place a second plate on top of the first plate so as to spread the liquid in a thin layer between the plates, and clamps the plates together.

How do you clean IR salt plate?

Cleaning salt plates: In the fume hood, using the halogenated waste bottle with a plastic funnel inserted into the top, place a salt plate into the funnel and rinse it with a little dichloromethane (methylene chloride). Allow it to dry (this is quick) and remove it by handling the edges of the salt plate only.

How do you clean salt plates?

“The best way to clean a salt plate is with an unused damp sponge,” Nick says. You can also scrub it with a mildly abrasive brush, then wipe it down with a damp cloth. Tackle tough, burned-on bits of food with a brush with a metal scraper brush.