ISSN:
0306-042X
Keywords:
Chemistry
;
Analytical Chemistry and Spectroscopy
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
The combination of pyrolysis and field ionization (Fl) mass spectrometry is used to characterize and identify mucous polysaccharides isolated from plant material (crude drugs). Oven pyrolysis is simply performed inside the ion source using a commercial direct introduction system. About 20μg of sample is thermally degraded by heating linearly from 50°C to 600°C at a rate of 0.4°C s-1.The thermal evaporation profiles and FI mass spectra of the pyrolysates of five pharmaceutically used plant mucilages were recorded and found to differ significantly from one another. The mass spectra show almost exclusively peaks corresponding to molecular ions of pyrolysis products which are characteristic for polysaccharides and demonstrate the presence of aldohexoses, aldopentoses and deoxyhexoses. The ratios of the characteristic signals of the dehydration products of these three groups of sugar subunits give semiquantitative information on the composition of these polysaccharides. The relative abundances of the key signals were compared with quantitative data obtained by classical methods, e.g. gas chromatography, and found to be a useful, indicative value.Comparison of the FI spectra of the mucilage pyrolysates with spectra of reference samples of mono- and oligosaccharides allows the identification of subunits in the sugar polymers. This is supported by the occurrence of their typical pyrolysis products which were assigned in previous pyrolysis studies.
Additional Material:
6 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/bms.1200090308
