| Wave number (cm−1)* | Bonds responsible for absorption |
| 3413 3226 3077 2941 2849 2500 1709
1615 1550 1449 1389 1300 1267 1216 1031 1035 | OH with hydrogen bonds OH with intermolecular bonds C-H of aromatics (related to organic matter) CH, aliphatic CH2 and CH3 lateral to aromatic nuclei carboxylic acid -OH Amine or amino acid derivatives C=O of various groups of carboxylic acids, cyclic and acyclic aldehydes and ketones C=C of double bonds in aliphatic and aromatic compounds. C=N of heterocyclics C-H of methyl and methylene groups Salts of the carboxylic acid groups C=N, NH (amide) C-O-CH3 aromatic C-The ester, ether and phenol Silicates O-CH3 |