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Sample Preparation. Solution-dissolve sample in halogenated solvent such as CCl4Neat liquid-small amount (1 drop) of sample on salt platesThin film-sheet of sample placed directly in IR beamPressed Pellet-small amount of solid sample mixed with KBr and pressed into a thin waferNujol-small amount
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1. IR Region of Electromagnetic Radiation 4000-600 cm-1 is most useful for identification of functional groups.
4000-1450 cm-1 is called the functional group region and is where characteristic signals for specific functional groups are most commonly found.
1450-600 cm-1 is called the fingerprint region because unique patterns for individual molecules are produced (often difficult to interpret).
2. Sample Preparation Solution-dissolve sample in halogenated solvent such as CCl4
Neat liquid-small amount (1 drop) of sample on salt plates
Thin film-sheet of sample placed directly in IR beam
Pressed Pellet-small amount of solid sample mixed with KBr and pressed into a thin wafer
Nujol-small amount of solid sample mixed with Nujol (mineral oil) and paste is applied to salt plates
3. Polystyrene Standard for IR