Pyridine, detection paper chromatography

De Whalley and his coworkers have made extensive studies on the application of paper chromatography to raffinose. To separate raffinose from large proportions of sucrose, a 1-butanol-benzene-pyridine-water solvent was used.140 81 To avoid pyridine, a 1-propanol-ethyl acetate-water mixture was recommended.141 As a color reagent, a-naph-thol-phosphoric acid was used. In this manner, less than 1 % of raffinose in cane sugar could be separated and determined. Partial hydrolysis of the raffinose, using invertase directly on the filter paper, proved useful in some instances.93 142 Melibiose was then detected with 3,5-dinitrosali-cylate142 or with diethyl-p-phenylenediamine sulfite.93... 

The decomposition products in irradiated solutions of polymyxin and in their hydrolysates were identified by paper electrophoresis in a pyridine-acetate buffer solution (pH 5.7, 1200 volts) and by paper chromatography using the systems butyl alcohol-acetic acid-water (4 1 5) and phenol-ethyl alcohol-water (2 1 1, in an NH3 atmosphere). For detection, ninhydrin and 2,4-dinitrophenyl hydrazine were used. 

Paper chromatography in ethyl acetate/pyridine/water 3.6 1 1.2 (upper phase) and thin-layer chromatography on silica gel G in ethyl acetate/acetonitrile/water 20 8 0.3 shows the presence of two compounds, A and B (detection with 5% KMn04 in 10% NaaCOs). The Rf values of A and B are 0.67 and 0.72 (paper chromatography) and 0.59 and 0.68 (thin-layer). 

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