It was reported by Okada and Shogenzi that there exist two kinds of organic acid (A
1 and A
2) and each dissociation constant is order of 10
-4∼10
-5 and 10
-11. But the natures of these two acids were not cleared up.
An attemp is made in this paper to consider these uncleared natures using the experimental result obtained by Okada and Shogenzi.
The result obtained may be summarized as :
(a) in view of the experimental result about the relation between the quantity of combined alkali and that of dissolved organic substances, it may be suggested that the organic substances which have acidic groups and combine with alkali are the pectine and lignin.
(b) comparing the dissociation constant of A
1 (10
-4∼10
-5) and of A2 (10
-11) obtained by experiment and that of the organic acids which have the carboxyl groups (10
-3∼10
-6) and of the phenol (1.05×10
-10), it may become considerably easier to understand that one of the two acids is pectine which have the carboxyl groups and the other is lignin which have the phenolic hydroxyl groups.
(c) further, we consider the ratio A
1/A
2 and their molecular weight and calculate them. These calculated values are in good agreement with observed values.
抄録全体を表示