The article deals with derivatization reactions employed in capillary elect
rophoresis (CE) of amino acids (AA). Currently preferred reactions are clas
sified into seven groups according to their reaction mechanisms and schemes
. Many of them were originally developed for liquid chromatography of AA an
d their implementation in CE usually requirer minor modifications of the wo
rking conditions depending on specificities of the process. So far, more th
an fifty derivatization reactions of AA have been reported in the literatur
e in the context of CE. This apparently reflects not only different reactiv
ities of AA with different derivatization agents but also different envisag
ed applications of CE. Therefore, in some instances, requirements for high
reaction rates determine the choice (e.g., post-column derivatizations of A
A, iri vivo monitoring of AA in microdialysates from biological processes).
On the other hand, a need for the detection of amol-zmol amounts of AA may
be often better met by the reactions characterized by lower reaction rates
. Some of the derivatization agents provide very selective detections of a
specific class of AA, e.g., detection of sulfanyl amino acids based on thei
r reactions with 2,2'-dinitro-5,5'-disulfonyl-dibenzoic acid. So far, only
a limited number of the derivatization reactions is applicable in the AA se
quenations of peptides and proteins by CE. Here, phenyl isothiocyanate, 7-(
N,N-dimethylsulfamoyl)-2, 1,3-benzoxadiazol-4-yl isothiocyanate and 1-fluor
o-2, 4-dinitrobenzene appear to have a prominent position.