Table 1.

Assignment of important Fourier-transform infrared (FTIR) spectral regions of biofluids.

Frequency (cm−1)	Spectral Region	Assignment
3000–2800	Fatty acids	dominated by fatty acid chains (e.g., phospholipids)
1800–1500	Proteins	dominated by conformation-sensitive amide I and amide II bands of proteins and peptides
1500–1200	Proteins and fatty acids (’mixed region’)	a region with complex absorption profiles from proteins as well as fatty acids
1230/1085	Phosphorus-containing biomolecules	detects vibrations of, for example, phospholipids or other phosphorus-containing biomolecules
1200–800	Polysaccharides	dominated by vibrations of various oligo- and poly-saccharides and their specific type of glycosidic linkages