Humic acid derivatives (HAD) from low rank Turkish brown coals

Humic acids are thought to be complex aromatic macromolecules with amino acids, amino sugars, peptides, and aliphatic compounds involved in linkages between the aromatic groups. Their importance in agriculture and soil sciences has been acknowledged for over 150 years. The brown coal or lignites differ considerably in mode of occurrence and in their physical and chemical properties, thus the variation in the amount of humic acids found in different deposits. To separate and identify the phenols from humic acids of the lignites, GC Hewlett-Packard 5790 and MS-VG 70-250-SE were used. The column was a 25 m x 2 mm i.d. with a film thickness of 0.25 mum Carbowax PEG 20 capillary glass.