腐植酸の形成に関する物理化学的研究 (第3報) : 腐植酸の吸収スペクトル (その2)

抄録

Visible and ultraviolet absorption spectra were determined with the alkaline solutions of humic acids extracted by hot dilute alkali from soils and peats pretreated by 5% hydrochloric acid or not (among these humic acids the former was named SrL humic acids and the latter, L humic acids). The results are summarized as follows : 1. The shapes of absorption curves of these humic acids were very similar to those extracted by SIMON'S method, (Fig, 1〜4). The fact that humification degree of humic acids could be shown by their absorption spectra, was furthermore vertified by these results. 2. Light absorption of SrL humic acid, obtained from soil, was generally greater than that of L humic acid of the same soil; but in the case of wet paddy soils and peats, light absorption of L humic acid was greater than that of SrL humic acids (Table 1 and 3). 3. SrL humic acids were fractionated by Mg^<++> into two parts, flocculated and non-flocculated; and the absorption spectra of both parts were determined and compared with each other (Table 2).