Preparing samples for IR spectroscopy involves different techniques depending on the form of the sample.
5 Essential Techniques for Preparing Samples for IR
1. Liquid Samples
Place a drop of the liquid on a highly polished salt plate, such as NaCl, AgCl, or KBr.
Place a second salt plate on top of the first one to spread the liquid in a thin layer between the plates.
Clamp the plates together to hold the sample in place.
2. Solid Samples
a) Mull Technique
Finely crush the solid sample.
Mix the crushed sample with a mulling agent, such as Nujol, in a marble or agate mortar using a pestle to make a thick paste.
Apply a thin film of the paste onto salt plates.
Mount the plates in the path of the IR beam and record the spectrum.
b) Solid Run in Solution
Dissolve the solid sample in a non-aqueous solvent, ensuring that there is no chemical interaction with the solvent and the solvent is not absorbed in the range to be studied.
Place a drop of the solution on the surface of an alkali metal disc.
Evaporate the solvent to dryness, leaving a thin film of the solute.
3. KBr Pellet Method
Press the powdered sample into a disc using a specific ratio of KBr to sample and a pressing load.
4. Nujol Method
Mix the powdered sample with a mulling agent to form a paste, which is then applied onto salt plates.
5. Diffuse Reflection Method, Attenuated Total Reflection (ATR), and Classic KBr Pellet Method
For powder samples, measurement methods such as the diffuse reflection method, attenuated total reflection (ATR), and the classic KBr pellet method are commonly used.
It's important to note that the material used for sample preparation must be transparent to IR radiation, hence the use of salts like NaCl, KBr, and AgCl.
Continue exploring, consult our experts
Looking for reliable laboratory equipment for IR spectroscopy? Look no further than KINTEK!
Our high-quality salt plates and alkali metal discs are perfect for preparing liquid and solid samples for accurate IR spectrum recording.
Trust KINTEK for all your laboratory equipment needs.
Visit our website or contact us today to place your order!
