|
R. S. Smirnov, A. D. Smolenkov, T. A. Bolotnik, O. A. Shpigun
Application of glyoxal and glyoxylic acid
for determination of n- and n,n- alkylsubstituted hydrazines by liquid
chromatography
Abstract
Using chromatography and spectrophotometry
for investigation of reaction of 1,1-dimethylhydrazine (UDMH), methylhydrazine
(MH) and 2-hydroxyethylhydrazine (HEH) with excess of glyoxal (Gl) and
glyoxylic acid (GlA) in aqueous solutions it was shown that corresponding
monohydrazone was produced as the single derivatization product. The
derivatization reaction is quantitative within 20 min at pH 3.5 and at 25 or 40 °C temperature for Gl and GlA respectively. Electronic absorption spectra of derivatives have maxima
in the range of 275–305 nm. The conditions for simultaneous determination of
hydrazines in water samples by RP–HPLC with UV-detection with preliminary
derivatization were proposed. The derivatives were separated on a Zorbax SB-C18
(150×4.6 mm) column with a mobile phase of 20 mM phosphate buffer solution (pH 3.5) – (2–5)% acetonitrile. The limits of detection were 0.25–0.5
or 0.4–0.7 µg/L for derivative of Gl and GlA respectively.
Key words: alkylhydrazines,
1,1-dimethylhydrazine, methylhydrazine, 2-hydroxyethylhydrazine, glyoxal,
glyoxylic acid, HPLC, water analysis.
Copyright (C) Chemistry Dept., Moscow State University, 2002
|
|
