Fulvic acids nuclear magnetic resonance

Cook, R. L. and Langford, C. H. (1998). Structural characterization of a fulvic acid and a humic acid using solid-state ramp-CP-MAS 13C nuclear magnetic resonance, Environ. Sci. Technol., 32, 719-725. 

Wilson et al. [2] carried out a compositional and solid state nuclear magnetic resonance (NMR) spectroscopic study of humic and fulvic acid and fractions present in soil organic matter. 

Fulvic and humic acids have been investigated with carbon-13 and proton nuclear magnetic resonance spectrometry, GC/MS, and IR spectroscopy. The fulvic and humic acids were found to be predominantly carboxylic and aromatic with a high proportion of 0- and Ji-substituted carbon atoms, although aliphatic ones were also observed. 

SOM, soil organic matter HS, humic substances DH, degree of humification HAC, humic acid C FAC, fulvic acid C TEC, total extractable C HR, humification rate HI, humification index NHC, nonhumified C TOC, total organic C HA, humic acid FA, fulvic acids UV-Vis, ultraviolet-visible FT-IR, Fourier transform infrared NMR, nuclear magnetic resonance ESR, electron spin resonance EEM, excitation-emission matrix. 

Lead, J. R., Wilkinson, K. J., Balnois, E., Cutak, B. J., Larive, C. K., Assemi, S., and Beckett, R. (2000). Diffusion coefficients and polydispersities of the Suwannee River Fulvic Acid Comparison of fluorescence correlation spectroscopy, pulsed-field gradient nuclear magnetic resonance, and flow field-flow fractionation. Environ. Sci. Technol. 34(16), 3508-3513. 

Hertkorn,N., Permin, A., Perminova, I., Kovalevskii, D., Yudov, M., Petrosyan, V., and Kettrup, A. (2002b). Comparative analysis of partial structures of a peat humic and fulvic acid using one- and two-dimensional nuclear magnetic resonance spectroscopy. /. Environ. Qual. 31, 375-387. 

Thorn K. A., Folan D. W., and MacCarthy P. (1992) Characterization of the International Humic Substances Society Standard and Reference Fulvic Acids by Solution State Carbon-13 and Hydrogen-1 Nuclear Magnetic Resonance Spectrometry. Water Resources Investigations Report 89-4196, U.S.G.S. Denver, 93pp. 

Thom, K.A. Folan, D.W. MacCarthy, P. Characterization of the international humic substances society standard and reference fulvic and humic acids by solution state carbon-13 O C) and hydrogen-1 OH) nuclear magnetic resonance spectroscopy , U.S. Geological Survey, Water Resource Investigations Report, Denver, Co, 1989 89-4196, pp. 1-4. 

NMR. Quantitative liquid-state carbon-13 nuclear magnetic resonance ( 3c NMR) spectra were recorded for humic and fulvic acid from Como Creek foam and for stream and foam fulvic- and humic- acid samples from the Suwannee River at the U.S. Geological Survey, laboratory in Arvada, CO. C NMR could not be performed on other humic substances due to insufficient sample or instrument availability. The acquisition parameters used were as follows C NMR spectra were recorded on a Varian XL-300 NMR spectrometer at 75 MHz. Each sample (200 mg of freeze-dried material) was dissolved in deuterated water and deuterated sodium hydroxide was added to ensure solution a total solution volume of approximately 6 to 7 mL. Spectra were recorded using a 30,000 Hz spectral window, a 45 pulse width, a 0.199 second acquisition time, and a pulse delay of 10 seconds for quantitative spectra. The number of transients was 10,000, and line broadening was 50 Hz. 

Saito, Y. and Hayano, S. (1981). Characterization of humic and fulvic acids isolated from marine sediments of Sagami and Suruga Bays with C and proton nuclear magnetic resonance. J. Oceanogr. Soc. Japan 36, No. 6, 286-292. 

Saleh, F. Y., Chang, D. Y., and Frye, J. S. (1983). Cross-polarization carbon-13 nuclear magnetic resonance and fast atom bombardment mass spectrometry of fractionated fulvic acid. Anal. Chem. 55, 862-866. 

Deczky, K., and Langford, H. (1978). Apphcation of water nuclear magnetic resonance relaxation times to study of metal complexes of the soluble soil organic matter fraction fulvic acid. Can. J. Chem. 56, 1947-1951. 

The study of humic substances by nuclear magnetic resonance of the isotope and the proton suggests that aliphatic structures prevail over aromatic structures for the fulvic acids extracted from marine water, contrary to the case for soil fulvic acids. The high values of the H C ratio in marine fulvic acids also point to an aliphatic nature (Stuermer and Payne, 1976). 

NMR spectra of (a) a soil humic acid (b) a groundwater fulvic acid (c) a mixture of C-methylated reference compounds (1) pentamethylquercetin (2) glycerol dimethyl ether (3) methyl benzoate (4) methyl pentanoate. Reprinted with permission from Mikita et al., Carbon-13 Enriched Nuclear Magnetic Resonance Method for the Determination of Hydroxyl Functionality in Humic Substances, Anal. Chem. 53, 1715-1717. Copyright 1981, American Chemical Society. 

Thorn, K. A. 1989. Nuclear-magnetic-resonance spectrometry investigations of fulvic and humic acids from the Suwanee River. In Thurman, E. M. and R. L. Malcolm. 1989. Nitrogen and amino acids in humic and fulvic acids from the Suwanee River. USGS Report 87-557, Denver, CO, pp. 251-309. 

Lead JR, Wilkinson KJ, Balnois E, Cutak BJ, Larive CK, Assemi S, Beckett R Diffusion Coefficients and Polydispersities of the Suwannee River Fulvic Acid Comparison of Fluorescence Correlation Spectroscopy, Pulsed-Field Gradient Nuclear Magnetic Resonance, and Flow Field-Flow Fractionation. Environ Sci Technol 2000, 34 3508-3513. 

---