Page 170 - Modern Derivatization Methods for Separation Sciences

Document Página 1 de 2

Page 75

Fig. 2.15.
Glyphosphate and its metabolite, AMPA.

Fig. 2.16.
Derivatives obtained in the reaction of DEMM with amino acids.

its chemical structure, it reacts with ninhydrin as much as AMPA. It can be assumed that during the
ninhydrin reaction, glyphosphate is converted into AMPA. For biological fluids, the minimum
detectable amount is 80 pmol.

2.2.8—
Diethylethoxymethylenemalonate (DEMM) [77]

Amino acids were determined by pre-column derivatization with DEMM and RP-HPLC with UV
detection at 280 nm. The limit of detection was 3 pmol with a signal-to-noise ratio of 5. This
derivatization of amino acids with DEMM and their subsequent RP-HPLC is recommended as an
alternative to the dedicated amino acid analyzer when subpicomole sensitivity is not required.
Formations of N-[2,2-bis(ethoxycarbonyl)vinyl] derivatives (Fig. 2.16) are stable for several weeks at
room temperature.

DEMM Application: Derivatization of Amino Acids [77]

http://emedia.netlibrary.com/nlreader/nlreader.dll?bookid=17968&filename=Page_75.html 30/09/2003