Fractionation of raw and methylated fulvic acids from lignite by thin-layer chromatography

Abstract Raw and methylated fulvic acids from lignite were subjected to thin-layer chromatography on silica gel, using the simplex method to optimize the eluant composition. The chromatograms did not show definite spots, but a continuous profile that could be resolved with a densitometer. Preparative TLC was carried out with the optimized eluant for each sample and the fractions obtained were analysed by i.r. spectrometry. Two different groups of fractions, resembling polysaccharides and phenolcarboxylic acids, were obtained from raw fulvic acids. Methylated fulvic acids did not show separation into different chemical types.