Guido Meyer, Renate Klöcking
Proceedings of the 14th International Peat Congress
humic-acid-precipitation, organic-acids, organohalogen-compounds, purification
Theme IV. Chemical, physical and biological characteristics of peat
Two modifications of the standard procedure for the isolation of humic acids from peat samples have been explored. The modifications comprise a Soxhlet-extraction of the freeze-dried peat sample with an organic solvent and the use of organic acids for the precipitation of the humic acid fraction. The organic extraction effectively removes organo-soluble impurities (up to 12 %) without any obvious sign of alteration or loss of humic material (Meyer, 2011). The use of organic acids as precipitant aims at the halogen and mineral acid free preparation of humic acids. In this article, the quality of humic acids obtained using the modified procedure is compared to those obtained by traditional HCl precipitation.