Abstract
The humic acid(HA) sample obtained from the alluvial soil was characterized by elemental composition, pyrolysis gas chromatography-mass spectrometry(Py-GC-MS) and solid-state 13C nuclear magnetic resonance (13C NMR) spectroscopy. There is high fat content and a few nitrogen-containing functional groups in HA. Py-GC-MS demonstrates the characterization and structural identification of HA. One long list of identified pyrolysis products was proposed for the construction of conceptual model of HA. Solid-state 13C NMR data indicate there are higher values of alkyl-C, O-alkyl-C and aryl-C in HA. The elemental composition, structural carbon distribution and 13C NMR spectroscopy of simulated HA are consistent with those of experimental HA. HyperChem® was used to simulate the three-dimensional molecular structure of the monomer, which was optimized by the molecular mechanics of the optimized potential for liquid simulations(OPLS) force field and molecular dynamics simulation to get the stable and balanced conformation. The deprotonation process study depicts that the degree of ionization of HA gets deeper, while the electronegativity of HA and the energy of van der Waals(vdW) increase. Moreover, the 3D structure of humic acid with −4 charges is the most stable. The deprotonation process is an endothermic process.
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Wang H. X., Yao L., Ding B., Luo J. H., Zhou G., Jiang B., Chem. J. Chinese Universities, 2013, 34(5), 1295
Diallo M. S., Simpson A., Gassman P. L., Faulon J. L., Johnson J. H., Goddard W. A., Hatcher P. G., Environ. Sci. Technol., 2003, 37, 1783
Niederer C., Goss K. U., Environ. Sci. Technol., 2007, 41, 3646
Albers C. N., Banta G. T., Jacobsen O. S., Hansen P. E., Eur. J. Soil Sci., 2008, 59, 693
Schaumann G. E., Thiele-Bruhn S., Geoderma, 2011, 166, 1
Chen Y. T., Ding J. D., Acta Polymerica Sinica, 2009, 12, 1238
Schulten H. R., Leinweber P., J. Anal. Appl. Pyrolysis, 1996, 38, 1
Swift R. S.; Ed.: Sparks D. L., Organic Matter Characterization, Methods of Soil Analysis, Soil Sci. Soc. Am., Madison, WI, 1996, 1018
HyperChem Release 7 for Windows, Hypercube Inc., Gainesville, 2002
Schulten H. R., Schnitzer M., Naturwissenschaften, 1995, 82, 487
Rosa de la J. M., González-Pérez J. A., González-Vila F. J., Knicker H., Araújo M. F., Org. Geochem., 2011, 42, 791
Lu X. Q., Hanna J. V., Johnson W. D., Appl. Geochem., 2000, 15, 1019
Schniter M., Khan S. U., Humic Substance in the Environment, Marcel Dekker Inc., New York, 1972, 23
Hautala K., Peuravuori J., Pihlaja K., Water Res., 2000, 34, 246
Baldock J. A., Skjemstad J. O., Org. Geochem., 2000, 31, 697
Yuan J. C., Liu Y. F., Mei T. J., Wang X. H., Chem. Res. Chinese Universities, 2011, 27(6), 1014
Hatcher P. G., Org. Geochem., 1987, 11, 31
Chen J. S., Chiu C. Y., Geoderma, 2003, 117, 129
Marche T., Schnitzer M., Dinel H., Paré T., Champagne P., Schulten H. R., Facey G., Geoderma, 2003, 116, 345
Malcolm R. L., MacCarthy P. L., Environ. Sci. Technol., 1986, 20, 904
Yarkova T. A., Gyul’maliev A. M., Solid Fuel Chem., 2012, 46, 279
Sein L. T., Varnum J. M., Jansen S. A., Environ. Sci. Technol., 1999, 33, 546
Fuchs W., Die Chemie der Kohle., Springer, Berlin, 1931, 501
Stevenson F. J., J. Environ. Qual., 1972, 1, 333
Schulten H. R., Leinweber P., Biol. Fertility Soils, 2000, 30, 399
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Supported by the National Natural Science Foundation of China(Nos.40771099, 41271331).
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Zhao, N., Lü, Yz. & Li, Gj. Characterization and three-dimensional structural modeling of humic acid via molecular mechanics and molecular dynamic simulation. Chem. Res. Chin. Univ. 29, 1180–1184 (2013). https://doi.org/10.1007/s40242-013-3156-x
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DOI: https://doi.org/10.1007/s40242-013-3156-x