The Occurrence of Fatty Acids in Fulvic Acid, A Soil Humic Fraction

1970 ◽  
Vol 8 (3) ◽  
pp. 505-512 ◽  
Author(s):  
M. Schnitzer ◽  
G. Ogner
Keyword(s):  
Fatty Acids ◽  
Fulvic Acid ◽  
Humic Fraction

Further Investigations on the Chemistry of Fulvic Acid, a Soil Humic Fraction

1971 ◽  
Vol 49 (13) ◽  
pp. 2302-2309 ◽  
Author(s):  
S. U. Khan ◽  
M. Schnitzer
Keyword(s):  
Fatty Acids ◽  
Hydrogen Bonds ◽  
Fulvic Acid ◽  
Phenolic Acids ◽  
Complex Structures ◽  
Isolation And Identification ◽  
Fractionation Scheme ◽  
Humic Fraction ◽  
Benzenecarboxylic Acids

The fractionation scheme described in this and in an earlier paper resulted in the isolation and identification of about 2.0 g of pure components from 100 g of fulvic acid. About 28% of these compounds were phenolic acids, 19% benzenecarboxylic acids, 13% alkanes and fatty acids, and 40% dialkyl phthalates. The isolation of appreciable amounts of dialkyl phthalates was somewhat surprising but their presence was shown not be an artifact. The KMnO4 oxidation of the same fractions increased the yields of methylated phenolic and benzenecarboxylic acids by between 3 and 11 times.Following KMnO4 oxidation of methylated but unfractioned fulvic acid, the yield of phenolic and benzenecarboxylic acids increased substantially. The increased yields, after oxidation, of the same compounds as those that were separated without oxidation indicate that either these compounds originated from more complex structures or that they came from a structure of the type proposed earlier, which consists of phenolic and benzenecarboxylic acids joined by hydrogen-bonds, on which alkanes, fatty acids, and dialkyl phthalates are adsorbed.

Fatty acids promote fulvic acid intercalation by montmorillonite

2014 ◽  
Vol 97-98 ◽  
pp. 53-61 ◽  
Author(s):  
William E. Dubbin ◽  
Jonathan P. Vetterlein ◽  
Jörgen L. Jonsson
Keyword(s):  
Fatty Acids ◽  
Fulvic Acid

The occurrence of alkanes in fulvic acid, a soil humic fraction

1970 ◽  
Vol 34 (8) ◽  
pp. 921-928 ◽  
Author(s):  
Gunnar Ogner ◽  
Morris Schnitzer
Keyword(s):  
Fulvic Acid ◽  
Humic Fraction

The Chemistry of High Molecular Weight Fulvic Acid Fractions

1974 ◽  
Vol 52 (24) ◽  
pp. 4123-4132 ◽  
Author(s):  
Jean A. Neyroud ◽  
Morris Schnitzer
Keyword(s):  
Fatty Acids ◽  
Molecular Weight ◽  
Ethyl Acetate ◽  
Fulvic Acid ◽  
Phenolic Acids ◽  
Degradation Products ◽  
Building Blocks ◽  
Oh Groups ◽  
Molecular Weights ◽  
Chemical Structures

Fulvic acid (FA) was methylated, dissolved in benzene, and fractionated over Al2O3 with the aid of organic solvents of increasing polarities. This paper is concerned with fractions eluted with ethyl acetate (III), ethyl acetate — methanol (1:1) (IV), and methanol (V), which were quantitatively the most abundant ones and which we consider as being most representative of the original FA. Each fraction was characterized by chemical and spectroscopic methods and by degradation with alkaline permanganate. Fractions IV and V were also degraded by NaOH hydrolysis and by alkaline CuO-oxidation. The degradation products were identified with the aid of a gas chromatograph — mass spectrometer — computer system.The number-average molecular weights of the three fractions were: III, 821; IV, 945; and V, 1,397. Infrared, proton n.m.r., and carbon-13 n.m.r. spectra provided, except for functional groups, little detailed information on the chemical structures of the fractions. The major degradation products were benzenecarboxylic and phenolic acids in addition to smaller amounts of aliphatic (mainly n-fatty) acids. Evidence is presented that may be interpreted to indicate: (a) esterification of some of the fatty acids to OH groups of phenolic acids; (b) the existence in the fractions of ether (C—O) linkages; and (c) rupture of C—C bonds during degradation. While in both the lower and the higher molecular weight FA fractions benzenecarboxylic and phenolic acids were the basic "building blocks", the latter appeared to be more complex and more stable in the higher-molecular weight fractions, possibly because chemical bonding as well as hydrogen bonding, van der Waal's forces, and π-bonding were involved simultaneously.

Chemistry of Fulvic Acid, a Soil Humic Fraction, and its Relation to Lignin

1971 ◽  
Vol 49 (7) ◽  
pp. 1053-1063 ◽  
Author(s):  
G. Ogner ◽  
M. Schnitzer
Keyword(s):  
Gas Chromatography ◽  
Hydrogen Bonding ◽  
Fulvic Acid ◽  
Water Soluble ◽  
Chromatographic Retention ◽  
Biological Oxidation ◽  
Polycarboxylic Acids ◽  
Preparative Gas Chromatography ◽  
Humic Fraction ◽  
Benzenecarboxylic Acids

Fulvic acid, a water-soluble soil humic fraction, was extracted from a Podzol soil and exhaustively methylated so as to make it soluble in benzene. The resulting material was separated repeatedly by column, thin layer, and preparative gas chromatography until relatively pure components were obtained. The latter were then identified by comparing their mass and micro-i.r. spectra and their gas chromatographic retention times with those of standards of known structures.Twenty-one phenolic and benzene-carboxylic acids were identified as methyl ethers and esters. In addition, a number of polymethoxy-benzene polycarboxylic acids of as yet unknown identity were isolated.A number of the compounds isolated have been reported to arise from the alkaline KMnO4 oxidation of lignin. Since we did not oxidize the fulvic acid in the laboratory, it is likely that it originated from products resulting from the chemical and/or biological oxidation of lignin in the soil. Methylation of the fulvic acid was necessary to make the compounds extractable by organic solvents. Since methylation reduces hydrogen-bonding in the fulvic acid, it is suggested that in fulvic acid phenolic and benzenecarboxylic acids are joined by hydrogen-bonds to form a polymeric structure of yet unknown conformation. Any weakening of hydrogen-bonding will lead to a break-up of this structure.

Fatty Acids and Glycerides

1979 ◽  
Vol 7 (4) ◽  
pp. 813-814
Author(s):  
J. L. HARWOOD
Keyword(s):  
Fatty Acids
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