Band positions cellulose

A very efficient thin layer form of circular paper chromatography makes use of a circular glass disc coated with an adsorbent (silica, alumina or cellulose). The apparatus is called a Chromatotron (available from Harrison Research, USA). The disc is rotated by a motor, and the sample followed by the eluting solvent are allowed to drip onto a central position on the plate. As the plate rotates the solvent elutes the mixture, centrifugally, while separating the components in the form of circles radiating from the central point. When elution is complete the revolving circular plate is stopped and the circular bands are scraped off and extracted with a suitable solvent. 

Table II lists the Raman peak positions for samples 4 and 11, which are typical of unbleached lignin-rich wood pulps. These peaks have been assigned in terms of contributions by cellulose and lignin. Raman contributions from hemicelluloses were expected to be broad and to occur at wavenumbers where cellulose contributions were detected. In Table II, certain bands are assigned to specific chemical-group vibrations. The assignment of bands to various groups in cellulose was based on literature [18]. The lignin-related assignments are based on the work described in this paper and the authors unpublished work.

Spectral Region 700-950 cm. The band at 895 cm" is discernible in wood and MP-6 (SCE temperature 250°C) but disappears from spectra of samples treated at higher temperatures where saccharides analysis has also shown the absence of cellulose. As carbonization proceeds, the out-of-plane bending below 900 cm" (at 870-881, 800-833 and 752-766 cm ) increases in intensity the position for some of the bands ( 800 and 750 cm ) can suggest condensed ring systems. 

---