Carbonyls, which are present in a large number of foods and natural pr
oducts, diversify in nature and significantly vary in amounts. They ar
e usually transformed to their 2,4-DNPHs for their analysis. A review
of the chromatographic (paper, TL, GL, HPL), spectroscopic/spectrophot
ometric (IR, UV, GC-MS), titrimetric and polarographic techniques appl
ied for identifying this important class of compounds has been present
ed in this manuscript.