Separation and Identification of Sugars using Paper Chromatography

Abstract

CHROMATOGRAPHY on filter paper has provided an excellent and a much-needed method for the investigation of the structure of polysaccharides^1–5 and proteins^6–10. While butanol–ethanol–water, butanol–acetic acid–water, and phenol–water are effective mixtures, among others¹, for the separation of a wide variety of sugars^11,12,5 and their methyl derivatives¹³, the phenol–water mixture is usually better than either of the other two mentioned above for the separation of unmethylated sugars (cf. ref. 14). The method using phenol–water, however, suffers from the disadvantage that the location of the sugars on the paper by treatment with ammoniacal silver nitrate cannot be accomplished without some difficulty because the paper quickly becomes dark or sometimes black. It is claimed that suitable purification of the phenol either reduces the darkening⁵ or eliminates it altogether¹⁵. We find that most of the darkening can be avoided by extracting the paper with ether before spraying with the silver reagent. By adopting this slight modification, it has been found unnecessary to purify the phenol.