I am extracting HA from river soil sediments and in the end of extraction we have to de ash the HA by HF and HCl. Can we use any other compound, chemical instead of HF to de ash the extracted HA. Your suggestions will be highly appreciated.
Dear Sir. Concerning your issue about the extraction of Humic acid from soil sediments. The humic acid was extracted from the sediments as outlined by Rashid and King (19691. The procedure , in brief, consists of extracting the humic acid from CO3-free sediment with 0.5 N sodium hydroxide solution . The extract is passed over Rexyn 101 exchange resin in the hydrogen form to remove sodium and other metal cations present in the extract . Th e purified extract is then acidified by HC1 to a pH of 3 to precipitate the humic acid. Th e precipitate is collected , washed , dialyzed against distilled water for several days, redissolved in 0.5 N NaOH solution and passed over the resin column several times. Finally it is freeze-dried . I think the following below links may help you in your analysis: