Sugars in environmental samples and sedimentary rocks – effectiveness in derivatization for GC-MS analysis

Abstract

Saccharides (sugars), common constituents of the bio- and geosphere, are useful in determining the source of organic matter (OM) in aerosols and early diagenetic phases. Due to the chemical properties and great diversity of sugars in nature, a wide range of techniques is used for the isolation and quantification of saccharides. Here, gas chromatography-mass spectrometry analysis, preceded by derivatization with N-methyl-N-trimethylsilyl-trifluoroacetamide (MSTFA) and N,O-bis(trimethylsilyl)trifluoroacetamide (BSTFA), was undertaken. The effectiveness of this derivatization was demonstrated for soils, aerosols, fungi, and individual sugar standards. The efficacy of BSTFA derivatization for individual sugar standards and, similarly, for samples of sugars in winter and summer aerosols was adequate. In fungi and soil samples, the MSTFA reagent was much more effective. Different mono- and disaccharides were identified in biological samples and sedimentary rocks, showing not only the great diversity of these compounds but also the specificity of their origin in recent and ancient OM. Greater variation in the occurrence of sugars in soils compared to rocks may suggest differences in the stability of some saccharides at an early stage of diagenetic transformation. Comparison of the occurrence of certain sugars in biological samples and sedimentary rocks sheds new light on the origin and preservation of these biomolecules.