Analytical pyrolysis of carbohydrates in the presence of hexamethyldisilazane

The paper describes gas chromatography/mass spectrometry (GC/MS) analysis of the products released from carbohydrates when flash pyrolysed in the presence of hexamethyldisilazane (HMDS). Monosaccharides (D-glucose, D-mannose, D-galactose) and polysaccharides (cellulose, laminaran, agar) were pyrolysed with HMDS using an off-line apparatus and on-line Py-GC/MS. A series of characteristic trimethylsilyl (TMS) ethers of hydroxylated compounds were released which are proposed as useful markers for the recognition of carbohydrates in complex matrices. The detected products included TMS derivatives of anhydrosugars, hydroxylated pyranones and cyclopentenones, hydroxymethylfuraldehyde, hydroxymethylfurane, di- and tri-hydroxybenzenes. Monosaccharides and related polymers yielded the TMS ethers of the corresponding 1,6anhydro-D-hexopyranoses and 1,6-anhydro-D-hexofuranoses which were identified by offline pyrolysis of the parent carbohydrate followed by silylation with HMDS.