STUDY ON THE DECOMPOSITION OF THE AMADORI COMPOUND N-(1-DEOXY-D-FRUCTOS-1-YL)-GLYCINE IN MODEL SYSTEMS - QUANTIFICATION BY FAST-ATOM-BOMBARDMENT TANDEM MASS-SPECTROMETRY

A new method for the quantification of N-(1-deoxy-D-fructos-1-yl)-glyc ine (DFG) was developed based on isotope dilution fast atom bombardmen t tandem mass spectrometry using C-13-labelled DFG as an internal stan dard. This method, which requires neither derivatization nor clean-up of the samples, was used to study the degradation of DFG under differe nt conditions (time and pH). It was found that the decomposition of DF G at 90 degrees C was favoured at pH 7 compared to pH 6. The higher st ability of DFG at pH 6 was due to 1,2-enolization leading to the relat ively stable 3-deoxglucosone.