Solution-state NMR investigation of the sorptive fractionation of dissolved organic matter by alkaline mineral soils
Perry J. Mitchell A , André J. Simpson A , Ronald Soong A , Adi Oren B , Benny Chefetz B and Myrna J. Simpson A C
+ Author Affiliations
- Author Affiliations
A Department of Chemistry and Environmental NMR Centre, University of Toronto, 1265 Military Trail, Toronto, ON, M1C 1A4, Canada.
B Department of Soil and Water Sciences, Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, PO Box 12, Rehovot 76100, Israel.
C Corresponding author. Email: myrna.simpson@utoronto.ca
Environmental Chemistry 10(4) 333-340 https://doi.org/10.1071/EN13052
Submitted: 9 March 2013 Accepted: 5 June 2013 Published: 16 August 2013
Environmental context. Dissolved organic matter plays a key role in global carbon cycling and environmental contaminant transport. We use one- and two-dimensional solution-state nuclear magnetic resonance spectroscopy to characterise dissolved organic matter before and after binding to alkaline subsoils with low organic carbon content. The results show that the dissolved organic matter is selectively fractionated through preferential binding of specific organic carbon functional groups.
Abstract. Sorption to clay minerals is a prominent fate of dissolved organic matter (DOM) in terrestrial environments. Previous studies have observed that DOM is selectively fractionated by interactions with both pure clay minerals and acidic mineral soils. However, the specific DOM functional groups that preferentially sorb to mineral surfaces in alkaline soils require further examination because higher basicity could change the nature of these sorptive interactions. Biosolids-derived DOM was characterised using one- and two-dimensional solution-state NMR spectroscopy before and after sorption to three alkaline subsurface mineral soils with varying mineralogy. Carboxylic DOM components sorbed preferentially to all soils, likely due to cation bridging and ligand exchange mechanisms. Aliphatic constituents were selectively retained only by a soil with high clay mineral content, possibly by van der Waals interactions with montmorillonite surfaces. Polar carbohydrate and peptide components of the DOM did not exhibit preferential sorption and may remain mobile in the soil solution and potentially stimulate microbial activity. A relatively low signal from aromatic DOM components prevented a full assessment of their sorption behaviour. The results suggest that DOM is selectively fractionated by similar interactions in both acidic and alkaline soils that may play a key role in the chemical and biochemical processes of subsurface environments.
Additional keywords: biosolids, clay minerals, preferential sorption, soil organic matter, subsurface soils.
References
[1] M. Guo, J. Chorover, Transport and fractionation of dissolved organic matter in soil columns. Soil Sci. 2003, 168, 108.| Transport and fractionation of dissolved organic matter in soil columns.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD3sXht1Wgsrw%3D&md5=69e77d6a11cf3da47246b88fcba8d0faCAS |
[2] K. Kaiser, K. Kalbitz, Cycling downwards – dissolved organic matter in soils. Soil Biol. Biochem. 2012, 52, 29.
| Cycling downwards – dissolved organic matter in soils.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC38XosVagsrw%3D&md5=896181e1c97fe78006bd30b7a3b15004CAS |
[3] C. R. Maxin, I. Kögel-Knabner, Partitioning of polycyclic aromatic hydrocarbons (PAH) to water-soluble soil organic matter. Eur. J. Soil Sci. 1995, 46, 193.
| Partitioning of polycyclic aromatic hydrocarbons (PAH) to water-soluble soil organic matter.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaK2MXotVantrs%3D&md5=6049c426bb15f9f802d3c451e798f0b3CAS |
[4] G. Sposito, Sorption of trace metals by humic materials in soils and natural waters. Crit. Rev. Environ. Control 1986, 16, 193.
| Sorption of trace metals by humic materials in soils and natural waters.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaL28XitVKjtLc%3D&md5=02b77f46e5c3394b52e4fea27871f9c6CAS |
[5] J. Chorover, M. K. Amistadi, Reaction of forest floor organic matter at goethite, birnessite and smectite surfaces. Geochim. Cosmochim. Acta 2001, 65, 95.
| Reaction of forest floor organic matter at goethite, birnessite and smectite surfaces.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD3MXitVygtg%3D%3D&md5=5f4ad74f68270eab1d93046506edd286CAS |
[6] B. Gu, J. Schmitt, Z. Chen, L. Liang, J. F. McCarthy, Adsorption and desorption of different organic matter fractions on iron oxide. Geochim. Cosmochim. Acta 1995, 59, 219.
| Adsorption and desorption of different organic matter fractions on iron oxide.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaK2MXjsFeksrY%3D&md5=25a5e8cec1683261d0988135fdce5a45CAS |
[7] B. Gu, J. Schmitt, Z. Chen, L. Liang, J. F. McCarthy, Adsorption and desorption of natural organic matter on iron oxide – mechanisms and models. Environ. Sci. Technol. 1994, 28, 38.
| Adsorption and desorption of natural organic matter on iron oxide – mechanisms and models.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaK2cXjslGmtA%3D%3D&md5=ccec6f9c795e37ab5da91d614bdee27eCAS | 22175831PubMed |
[8] K. Kaiser, G. Guggenberger, L. Haumaier, W. Zech, Dissolved organic matter sorption on subsoils and minerals studied by 13C NMR and DRIFT spectroscopy. Eur. J. Soil Sci. 1997, 48, 301.
| Dissolved organic matter sorption on subsoils and minerals studied by 13C NMR and DRIFT spectroscopy.Crossref | GoogleScholarGoogle Scholar |
[9] D. M. McKnight, K. E. Bencala, G. W. Zellweger, G. R. Aiken, G. L. Feder, K. A. Thorn, Sorption of dissolved organic carbon by hydrous aluminum and iron oxides occurring at the confluence of Deer Creek with the Snake River, Summit County, Colorado. Environ. Sci. Technol. 1992, 26, 1388.
| Sorption of dissolved organic carbon by hydrous aluminum and iron oxides occurring at the confluence of Deer Creek with the Snake River, Summit County, Colorado.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaK38XktFeqt7c%3D&md5=d78b8e08faabf8f006f268f85e9b4e35CAS |
[10] G. U. Balcke, N. A. Kulikova, S. Hesse, F. D. Kopinke, I. V. Perminova, F. H. Frimmel, Adsorption of humic substances onto kaolin clay related to their structural features. Soil Sci. Soc. Am. J. 2002, 66, 1805.
| Adsorption of humic substances onto kaolin clay related to their structural features.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD38XoslKhsLw%3D&md5=38f31d4fae9c63d07aca52781f6ed32bCAS |
[11] X. Feng, A. J. Simpson, M. J. Simpson, Chemical and mineralogical controls on humic acid sorption to clay mineral surfaces. Org. Geochem. 2005, 36, 1553.
| Chemical and mineralogical controls on humic acid sorption to clay mineral surfaces.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD2MXhtFGhsbnL&md5=44474f7e0b99cf63d5ba1bffcf21e65bCAS |
[12] A. J. Simpson, M. J. Simpson, W. L. Kingery, B. A. Lefebvre, A. Moser, A. J. Williams, M. Kvasha, B. P. Kelleher, The application of 1H high-resolution magic-angle spinning NMR for the study of clay-organic associations in natural and synthetic complexes. Langmuir 2006, 22, 4498.
| The application of 1H high-resolution magic-angle spinning NMR for the study of clay-organic associations in natural and synthetic complexes.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD28XjtFWrtLo%3D&md5=416579a9507493665bc3b7fa6ea6f49eCAS | 16649755PubMed |
[13] L. Zhang, L. Luo, S. Zhang, Integrated investigations on the adsorption mechanisms of fulvic and humic acids on three clay minerals. Colloids Surf. A 2012, 406, 84.
| Integrated investigations on the adsorption mechanisms of fulvic and humic acids on three clay minerals.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC38XotlSgurc%3D&md5=667dee9fabbd125e410fd31703bfe162CAS |
[14] A. Oren, B. Chefetz, Sorptive and desorptive fractionation of dissolved organic matter by mineral soil matrices. J. Environ. Qual. 2012, 41, 526.
| Sorptive and desorptive fractionation of dissolved organic matter by mineral soil matrices.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC38Xkt1ylurY%3D&md5=c5ede9db2b5db00ee4039dc18dc01be0CAS | 22370415PubMed |
[15] B. G. Pautler, G. C. Woods, A. Dubnick, A. J. Simpson, M. J. Sharp, S. J. Fitzsimons, M. J. Simpson, Molecular characterization of dissolved organic matter in glacial ice: coupling natural abundance 1H NMR and fluorescence spectroscopy. Environ. Sci. Technol. 2012, 46, 3753.
| Molecular characterization of dissolved organic matter in glacial ice: coupling natural abundance 1H NMR and fluorescence spectroscopy.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC38XjtFWhsLk%3D&md5=9014a14500d676f47a09696080b65478CAS | 22385100PubMed |
[16] B. Lam, A. Baer, M. Alaee, B. Lefebvre, A. Moser, A. Williams, A. J. Simpson, Major structural components in freshwater dissolved organic matter. Environ. Sci. Technol. 2007, 41, 8240.
| Major structural components in freshwater dissolved organic matter.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD2sXht1OhsLfI&md5=7a575e6a466d3787a0ff4083a665cb1bCAS | 18200846PubMed |
[17] N. Hertkorn, R. Benner, M. Frommberger, P. Schmitt-Kopplin, M. Witt, K. Kaiser, A. Kettrup, J. I. Hedges, Characterization of a major refractory component of marine dissolved organic matter. Geochim. Cosmochim. Acta 2006, 70, 2990.
| Characterization of a major refractory component of marine dissolved organic matter.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD28XlsFGjurc%3D&md5=4140cb5333c96b0490324ba7a17c28c6CAS |
[18] G. C. Woods, M. J. Simpson, P. J. Koerner, A. Napoli, A. J. Simpson, HILIC-NMR: toward the identification of individual molecular components in dissolved organic matter. Environ. Sci. Technol. 2011, 45, 3880.
| HILIC-NMR: toward the identification of individual molecular components in dissolved organic matter.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC3MXkt1ylur8%3D&md5=8472058774280fd59b921cf425248171CAS | 21469703PubMed |
[19] M. Kleber, P. Sollins, R. Sutton, A conceptual model of organo–mineral interactions in soils: self-assembly of organic molecular fragments into zonal structures on mineral surfaces. Biogeochemistry 2007, 85, 9.
| A conceptual model of organo–mineral interactions in soils: self-assembly of organic molecular fragments into zonal structures on mineral surfaces.Crossref | GoogleScholarGoogle Scholar |
[20] J. C. Joo, C. D. Shackelford, K. F. Reardon, Association of humic acid with metal (hydr)oxide-coated sands at solid–water interfaces. J. Colloid Interface Sci. 2008, 317, 424.
| Association of humic acid with metal (hydr)oxide-coated sands at solid–water interfaces.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD2sXhtlChurbI&md5=84f387e05bfd6e7b259b08565d9ae44dCAS | 17963778PubMed |
[21] K. Kaiser, G. Guggenberger, L. Haumaier, Changes in dissolved lignin-derived phenols, neutral sugars, uronic acids, and amino sugars with depth in forested haplic arenosols and rendzic leptosols. Biogeochemistry 2004, 70, 135.
| Changes in dissolved lignin-derived phenols, neutral sugars, uronic acids, and amino sugars with depth in forested haplic arenosols and rendzic leptosols.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD2cXhtVais7bP&md5=5fd2bcdea0317ca5b3d4dfb40ffbeb08CAS |
[22] T. Polubesova, Y. Chen, R. Navon, B. Chefetz, Interactions of hydrophobic fractions of dissolved organic matter with Fe3+- and Cu2+-montmorillonite. Environ. Sci. Technol. 2008, 42, 4797.
| Interactions of hydrophobic fractions of dissolved organic matter with Fe3+- and Cu2+-montmorillonite.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD1cXmtFWgsrs%3D&md5=6ec7dc8b1555b802aa92292a13a10efcCAS | 18678008PubMed |
[23] P. S. M. Santos, E. B. H. Santos, A. C. Duarte, First spectroscopic study on the structural features of dissolved organic matter isolated from rainwater in different seasons. Sci. Total Environ. 2012, 426, 172.
| First spectroscopic study on the structural features of dissolved organic matter isolated from rainwater in different seasons.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC38XmvFSjsLo%3D&md5=1935bd6798cbd2197e9d32b28635b016CAS |
[24] G. C. Woods, M. J. Simpson, B. G. Pautler, S. F. Lamoureux, M. J. Lafrenière, A. J. Simpson, Evidence for the enhanced lability of dissolved organic matter following permafrost slope disturbance in the Canadian High Arctic. Geochim. Cosmochim. Acta 2011, 75, 7226.
| Evidence for the enhanced lability of dissolved organic matter following permafrost slope disturbance in the Canadian High Arctic.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC3MXhtlyjt7zN&md5=a32f11da171e9343758a37a4297794c7CAS |
[25] C. A. Thimsen, R. G. Keil, Potential interactions between sedimentary dissolved organic matter and mineral surfaces. Mar. Chem. 1998, 62, 65.
| Potential interactions between sedimentary dissolved organic matter and mineral surfaces.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaK1cXksVWlurg%3D&md5=56227de5a6e0fd9e6568c4fc69174cc0CAS |
[26] K. Kaiser, G. Guggenberger, The role of DOM sorption to mineral surfaces in the preservation of organic matter in soils. Org. Geochem. 2000, 31, 711.
| The role of DOM sorption to mineral surfaces in the preservation of organic matter in soils.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD3cXmsFSqu7o%3D&md5=2966b93313362a9bed1a3d06bc59777aCAS |
[27] K. Kaiser, W. Zech, Sorption of dissolved organic nitrogen by acid subsoil horizons and individual mineral phases. Eur. J. Soil Sci. 2000, 51, 403.
| Sorption of dissolved organic nitrogen by acid subsoil horizons and individual mineral phases.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD3cXntFGjtrk%3D&md5=c68cfc2c025bc6c8c867381b39321767CAS |
[28] M. Kahle, M. Kleber, R. Jahn, Retention of dissolved organic matter by illitic soils and clay fractions: Influence of mineral phase properties. J. Plant Nutr. Soil Sci. 2003, 166, 737.
| Retention of dissolved organic matter by illitic soils and clay fractions: Influence of mineral phase properties.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD2cXhsVGnug%3D%3D&md5=e3ffcc8c1409154271f00bd645762bdeCAS |
[29] K. Wang, B. Xing, Structural and sorption characteristics of adsorbed humic acid on clay minerals. J. Environ. Qual. 2005, 34, 342.
| Structural and sorption characteristics of adsorbed humic acid on clay minerals.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD2MXotlSgsw%3D%3D&md5=79b266ed3f52db818bf54b8d2584c829CAS | 15647564PubMed |
[30] Y. Shen, Sorption of natural dissolved organic matter on soil. Chemosphere 1999, 38, 1505.
| Sorption of natural dissolved organic matter on soil.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaK1MXhsFSktLo%3D&md5=28e654b52431a90b464d1f384e9306d6CAS |
[31] K. Kaiser, G. Guggenberger, W. Zech, Sorption of DOM and DOM fractions to forest soils. Geoderma 1996, 74, 281.
| Sorption of DOM and DOM fractions to forest soils.Crossref | GoogleScholarGoogle Scholar |
[32] C. Rumpel, I. Kögel-Knabner, Deep soil organic matter – a key but poorly understood component of terrestrial C cycle. Plant Soil 2011, 338, 143.
| Deep soil organic matter – a key but poorly understood component of terrestrial C cycle.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC3cXhsFKmtLrE&md5=dfdc15b9077aeb04ac0f16d86d483faeCAS |
[33] D. N. Kothawala, C. Roehm, C. Blodau, T. R. Moore, Selective adsorption of dissolved organic matter to mineral soils. Geoderma 2012, 189–190, 334.
| Selective adsorption of dissolved organic matter to mineral soils.Crossref | GoogleScholarGoogle Scholar |
[34] M. V. McCaul, D. Sutton, A. J. Simpson, A. Spence, D. J. McNally, B. W. Moran, A. Goel, B. O’Connor, K. Hart, B. P. Kelleher, Composition of dissolved organic matter within a lacustrine environment. Environ. Chem. 2011, 8, 146.
| Composition of dissolved organic matter within a lacustrine environment.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC3MXmt1yisr8%3D&md5=cac5eb3b458ee3abb7e74a091bce3718CAS |
[35] B. G. Pautler, A. J. Simpson, M. J. Simpson, L. Tseng, M. Spraul, A. Dubnick, M. J. Sharp, S. J. Fitzsimons, Detection and structural identification of dissolved organic matter in Antarctic glacial ice at natural abundance by SPR-W5-WATERGATE 1H NMR spectroscopy. Environ. Sci. Technol. 2011, 45, 4710.
| Detection and structural identification of dissolved organic matter in Antarctic glacial ice at natural abundance by SPR-W5-WATERGATE 1H NMR spectroscopy.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC3MXlsFWnu70%3D&md5=a92d644cddfe3844722f901aca869d78CAS | 21542577PubMed |
[36] G. C. Woods, M. J. Simpson, A. J. Simpson, Oxidized sterols as a significant component of dissolved organic matter: evidence from 2D HPLC in combination with 2D and 3D NMR spectroscopy. Water Res. 2012, 46, 3398.
| Oxidized sterols as a significant component of dissolved organic matter: evidence from 2D HPLC in combination with 2D and 3D NMR spectroscopy.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC38XlsVWrsr0%3D&md5=d0f057db0fe4965359b38bfc138a4937CAS | 22503587PubMed |
[37] O. Pisani, Y. Yamashita, R. Jaffé, Photo-dissolution of flocculent, detrital material in aquatic environments: contributions to the dissolved organic matter pool. Water Res. 2011, 45, 3836.
| Photo-dissolution of flocculent, detrital material in aquatic environments: contributions to the dissolved organic matter pool.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC3MXnvFOrtr0%3D&md5=29793b2d198c8196c5e67274c66fdb52CAS | 21570101PubMed |
[38] R. Jaffé, Y. Yamashita, N. Maie, W. T. Cooper, T. Dittmar, W. K. Dodds, J. B. Jones, T. Myoshi, J. R. Ortiz-Zayas, D. C. Podgorski, A. Watanabe, Dissolved organic matter in headwater streams: compositional variability across climatic regions of North America. Geochim. Cosmochim. Acta 2012, 94, 95.
| Dissolved organic matter in headwater streams: compositional variability across climatic regions of North America.Crossref | GoogleScholarGoogle Scholar |
[39] D. L. Sparks, Methods of Soil Analysis. Part 3: Chemical Methods 1996 (Soil Science Society of America: Madison, WI).
[40] J. H. Dane, G. C. Topp, Methods of Soil Analysis. Part 4: Physical Methods 2002 (Soil Science Society of America: Madison, WI).
[41] A. Walkley, I. A. Black, An examination of Degtjareff method for determining soil organic matter, and a proposed modification of the chromic acid titration method. Soil Sci. 1934, 37, 29.
| An examination of Degtjareff method for determining soil organic matter, and a proposed modification of the chromic acid titration method.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaA2cXitlGmug%3D%3D&md5=cf35b840ec54ab388bc3599b0fb466f8CAS |
[42] K. L. Sahrawat, Simple modification of the Walkley–Black method for simultaneous determination of organic carbon and potentially mineralizable nitrogen in tropical rice soils. Plant Soil 1982, 69, 73.
| Simple modification of the Walkley–Black method for simultaneous determination of organic carbon and potentially mineralizable nitrogen in tropical rice soils.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaL3sXntVylug%3D%3D&md5=f75eb08f2de398fafbae97ae32a5568aCAS |
[43] O. P. Mehra, M. L. Jackson, Iron oxide removal from soils and clays by dithionite-citrate systems buffered with sodium bicarbonate. Clays Clay Miner. 1958, 7, 317.
| Iron oxide removal from soils and clays by dithionite-citrate systems buffered with sodium bicarbonate.Crossref | GoogleScholarGoogle Scholar |
[44] A. J. Simpson, S. A. Brown, N. M. R. Purge, Effective and easy solvent suppression. J. Magn. Reson. 2005, 175, 340.
| Effective and easy solvent suppression.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD2MXls1ygsrY%3D&md5=851c2354b5474916aefd5a7ef085d21cCAS | 15964227PubMed |
[45] D. H. Wu, A. D. Chen, C. S. Johnson, An improved diffusion-ordered spectroscopy experiment incorporating bipolar-gradient pulses. J. Magn. Reson. A 1995, 115, 260.
| An improved diffusion-ordered spectroscopy experiment incorporating bipolar-gradient pulses.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaK2MXnsVGht7k%3D&md5=03794e197acc0553d63423a65b149decCAS |
[46] B. G. Pautler, A. J. Simpson, D. J. McNally, S. F. Lamoureux, M. J. Simpson, Arctic permafrost active layer detachments stimulate microbial activity and degradation of soil organic matter. Environ. Sci. Technol. 2010, 44, 4076.
| Arctic permafrost active layer detachments stimulate microbial activity and degradation of soil organic matter.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC3cXlvVakt7k%3D&md5=3492aed739a565555c2d2e2bdabbff78CAS | 20459054PubMed |
[47] A. Singer, The Soils of Israel 2007 (Springer: New York).
[48] D. L. Sparks, Environmental Soil Chemistry 2003 (Academic Press: San Diego, CA).
[49] G. C. Woods, M. J. Simpson, B. P. Kelleher, M. McCaul, W. L. Kingery, A. J. Simpson, Online high-performance size exclusion chromatography-nuclear magnetic resonance for the characterization of dissolved organic matter. Environ. Sci. Technol. 2010, 44, 624.
| Online high-performance size exclusion chromatography-nuclear magnetic resonance for the characterization of dissolved organic matter.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD1MXhsF2gsbfN&md5=247e8945135ba2237e5ca142663eb5c3CAS | 20030309PubMed |
[50] H. Gest, Evolution of the citric acid cycle and respiratory energy conversion in prokaryotes. FEMS Microbiol. Lett. 1981, 12, 209.
| Evolution of the citric acid cycle and respiratory energy conversion in prokaryotes.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaL38Xjtlem&md5=014a5fb9dbb23a052a65b44d885c47a4CAS |
[51] B. Schink, J. G. Zeikus, Microbial methanol formation - a major end product of pectin metabolism. Curr. Microbiol. 1980, 4, 387.
| Microbial methanol formation - a major end product of pectin metabolism.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaL3MXpvFGjtg%3D%3D&md5=d9c990534ba80322a8b658efad0629cdCAS |
[52] V. Brochier, P. Gourland, M. Kallassy, M. Poitrenaud, S. Houot, Occurrence of pathogens in soils and plants in a long-term field study regularly amended with different composts and manure. Agric. Ecosyst. Environ. 2012, 160, 91.
| Occurrence of pathogens in soils and plants in a long-term field study regularly amended with different composts and manure.Crossref | GoogleScholarGoogle Scholar |
[53] T. B. Prakasam, N. C. Dondero, Aerobic heterotrophic bacterial populations of sewage and activated sludge. 5. Analysis of population structure and activity. Appl. Microbiol. 1970, 19, 671.
| 1:CAS:528:DyaE3cXktVKqtL8%3D&md5=ebbfcfa5cf663e8d55bbc474bfa6d386CAS | 5418947PubMed |
[54] A. Munnich, Casting an eye on the Krebs cycle. Nat. Genet. 2008, 40, 1148.
| Casting an eye on the Krebs cycle.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD1cXhtFKht73E&md5=ec6cc532b7dacd692ab159c5d02a6c85CAS | 18818715PubMed |
[55] J. Hur, M. A. Schlautman, Molecular weight fractionation of humic substances by adsorption onto minerals. J. Colloid Interface Sci. 2003, 264, 313.
| Molecular weight fractionation of humic substances by adsorption onto minerals.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD3sXmtFagt7w%3D&md5=fb6d1b0a6744ce049831a5cc65203501CAS | 16256646PubMed |
[56] M. Ochs, B. Ćosović, W. Stumm, Coordinative and hydrophobic interaction of humic substances with hydrophilic Al2O3 and hydrophobic mercury surfaces. Geochim. Cosmochim. Acta 1994, 58, 639.
| Coordinative and hydrophobic interaction of humic substances with hydrophilic Al2O3 and hydrophobic mercury surfaces.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaK2cXhs12gt7Y%3D&md5=457a20107556a3901653f38a9c7694d6CAS |
[57] Q. Zhou, P. A. Maurice, S. E. Cabaniss, Size fractionation upon adsorption of fulvic acid on goethite: equilibrium and kinetic studies. Geochim. Cosmochim. Acta 2001, 65, 803.
| Size fractionation upon adsorption of fulvic acid on goethite: equilibrium and kinetic studies.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD3MXhs1Sru7o%3D&md5=a53353587e4889da433bd815d2414d33CAS |
[58] F. Sánchez-Patán, M. Monagas, M. V. Moreno-Arribas, B. Bartolomé, Determination of microbial phenolic acids in human faeces by UPLC-ESI-TQ MS. J. Agric. Food Chem. 2011, 59, 2241.
| Determination of microbial phenolic acids in human faeces by UPLC-ESI-TQ MS.Crossref | GoogleScholarGoogle Scholar | 21366314PubMed |
[59] A. J. Simpson, D. J. McNally, M. J. Simpson, NMR spectroscopy in environmental research: from molecular interactions to global processes. Prog. Nucl. Magn. Reson. Spectrosc. 2011, 58, 97.
| NMR spectroscopy in environmental research: from molecular interactions to global processes.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC3MXjtVKruro%3D&md5=cdfe59d3b5d7b0c93fd965383a040f99CAS | 21397118PubMed |
[60] E. G. Piotrowski, K. M. Valentine, P. E. Pfeffer, Solid-state, 13C, cross-polarization, magic angle spinning, NMR spectroscopy studies of sewage sludge. Soil Sci. 1984, 137, 194.
| Solid-state, 13C, cross-polarization, magic angle spinning, NMR spectroscopy studies of sewage sludge.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaL2cXhsl2ksrw%3D&md5=d6f2264516857555d3893b5b3b881c67CAS |
[61] A. J. Simpson, G. Song, E. Smith, B. Lam, E. H. Novotny, M. H. B. Hayes, Unraveling the structural components of soil humin by use of solution-state nuclear magnetic resonance spectroscopy. Environ. Sci. Technol. 2007, 41, 876.
| Unraveling the structural components of soil humin by use of solution-state nuclear magnetic resonance spectroscopy.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD28XhtlWmu7%2FE&md5=af3ccd56637206cad00bfd2858459f20CAS | 17328197PubMed |
[62] K. Kaiser, G. Guggenberger, Sorptive stabilization of organic matter by microporous goethite: sorption into small pores vs. surface complexation. Eur. J. Soil Sci. 2007, 58, 45.
| Sorptive stabilization of organic matter by microporous goethite: sorption into small pores vs. surface complexation.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD2sXjsVOhtb8%3D&md5=60851c93d9a4032ec0868514a5d17d3cCAS |
[63] J. G. Kerr, M. C. Eimers, Decreasing soil water Ca2+ reduces DOC adsorption in mineral soils: implications for long-term DOC trends in an upland forested catchment in southern Ontario, Canada. Sci. Total Environ. 2012, 427–428, 298.
| Decreasing soil water Ca2+ reduces DOC adsorption in mineral soils: implications for long-term DOC trends in an upland forested catchment in southern Ontario, Canada.Crossref | GoogleScholarGoogle Scholar | 22554533PubMed |
[64] H. Fischer, A. Meyer, K. Fischer, Y. Kuzyakov, Carbohydrate and amino acid composition of dissolved organic matter leached from soil. Soil Biol. Biochem. 2007, 39, 2926.
| Carbohydrate and amino acid composition of dissolved organic matter leached from soil.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD2sXpt1Cgt70%3D&md5=7e8a1a20cde6d48185326c032a8e6fdbCAS |
[65] M. J. Simpson, A. J. Simpson, The chemical ecology of soil organic matter molecular constituents. J. Chem. Ecol. 2012, 38, 768.
| The chemical ecology of soil organic matter molecular constituents.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC38Xptl2ltbs%3D&md5=92f1fabf58a71e4c48eb5adc62337cbdCAS | 22549555PubMed |
