hu·mic acid /ˈhjumɪk, ˈju-/ 名詞
腐殖酸,黑腐酸
Hu·min n. Chem. A bitter, brownish yellow, amorphous substance, extracted from vegetable mold, and also produced by the action of acids on certain sugars and carbohydrates; -- called also humic acid, ulmin, gein, ulmic or geic acid, etc.
◄ ►
humic acid
n : a dark brown humic substance that is soluble in water only
at pH values greater than 2; "the half-life of humic acid
is measured in centuries"