P. Husek, CHLOROFORMATES IN GAS-CHROMATOGRAPHY AS GENERAL-PURPOSE DERIVATIZING AGENTS, Journal of chromatography B. Biomedical sciences and applications, 717(1-2), 1998, pp. 57-91
Citations number
99
Categorie Soggetti
Chemistry Analytical","Biochemical Research Methods
Journal title
Journal of chromatography B. Biomedical sciences and applications
Chloroformates with simplest alkyls, i.e. methyl, ethyl or isobutyl, a
lready known as favourable reagents for treating amino groups in gas c
hromatography for years, were revealed randomly as exceptionally rapid
esterification agents. Unlike the rather poor results achieved with c
hloroformate-mediated ester formation in organic chemistry, the pyridi
ne-catalyzed esterification of carboxylic acids appeared to proceed at
the analytical microscale smoothly. Along with the catalyzer, an alco
hol should also be present in the medium, accompanied by acetonitrile
or water, according to the character of the compounds treated. Reactio
n conditions were optimized for various classes of carboxylic acids an
d a uniquely rapid derivatization of amino acids in aqueous ethanol wa
s shown to be possible. Most of the analytes, e.g. acidic metabolites
in physiological fluids, could be treated directly in the aqueous matr
ix. A simultaneous analysis of, e.g., amino and fatty acids or amines
and their acidic catabolytes was proven to be possible. Along with the
low-molecular-mass reagents, still some others, i.e, the hexyl, menth
yl or pentafluorobenzyl ones, found their application fields. Results
of optimized reaction conditions and a wide range of applications of c
hloroformate-mediated derivatization in various disciplines have been
summarized in this review. (C) 1998 Elsevier Science B.V. All rights r
eserved.