| 摘要 |
PURPOSE: A humic acid and fulvic acid sampling method from a natural humic substance is provided to obtain humic acid and fulvic acid in the high efficiency and high purity. CONSTITUTION: A humic acid and fulvic acid sampling method from a natural humic substance comprises the following steps: mixing the natural humic substance with a NaOH aqueous solution for the alkali extraction, and removing insoluble materials from the mixture to obtain a solution; adding hydrochloric acid into the solution until the pH of the mixture of 1.5, and centrifugal separating the mixture to obtain the precipitate; and washing the precipitate with a mixture of the hydrochloric acid and hydrofluoric acid. |
