STABLE ISOTOPIC ANALYSIS OF INDIVIDUAL CARBOHYDRATES BY GAS CHROMATOGRAPHIC/COMBUSTION/ISOTOPE RATIO MASS SPECTROMETRY

Abstract

Through the gas chromatographic/combustion/isotope ratio mass spectrometry (GC/C/IRMS) determinations of alditol acetate derivatives of monosaccharides, rapid analysis of the δ13C of individual sugars can be accomplished with a precision of approximately +/-0.3%%. Fractionations in carbon occurring during the bond rupture/derivatization procedure are reproducible, and thus permit the back calculation to the original isotopic composition of the sugar prior to the addition of the acetate groups. Limitations exist in the methodology, including the production of asymmetric carbon center during reduction steps, which need to be considered in interpretation of both chemical and isotopic results.