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Molecular and Equivalent Weights of the Organic Matter of a Podzol
Author(s) -
Schnitzer M.,
Desjardins J. G.
Publication year - 1962
Publication title -
soil science society of america journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.836
H-Index - 168
eISSN - 1435-0661
pISSN - 0361-5995
DOI - 10.2136/sssaj1962.03615995002600040017x
Subject(s) - podzol , chemistry , organic matter , sulfolane , potentiometric titration , polyatomic ion , molecule , molecular mass , ion , organic chemistry , soil water , geology , soil science , solvent , enzyme
The number‐average molecular weights of the organic matter of the A 0 and B h horiozons of a Podzol, determined by freezing point depression in sulfolane, were 1684 and 669, respectively. From the molecular weights, in conjunction with ultimate and functional group analyses, molecular formulae were calculated. These were C 75 H 33 O 17 N 3 (COOH) 3 (OH) 12 (CO) 2 for the A 0 and C 21 H 12 (COOH) 6 (OH) 5 (CO) 2 for the B h organic matter. The presence of relatively large numbers of functional groups in the B h molecule offers interesting possibilities for metallo‐organic interactions. The equivalent weights of the same organic matter preparations, measured by discontinuous potentiometric titrations, were 165 for the A 0 and 76 for the B h organic matter. The ratio of molecular to equivalent weight was 10 for the A 0 and 9 for the B h material. These ratios were in both cases equal to the sum of carboxyl plus phenolic hydroxyl groups in the two molecules.