Humic Substances from Podzols Under Oak Forest and a Cleared Forest Site I. Isolation and Characterization

Simpson, André J.; Watt, B.E.; Graham, C.L.; Hayes, M.H.B.

doi:10.1016/b978-1-85573-805-8.50010-0

Cited by 12 publications

(11 citation statements)

References 4 publications

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“…According to the results of graphical-statistic analysis, FAs contain more acids and less carbon in contrast to HAs and so have remarkably substituted aromatic rings and developed side aliphatic chains. The obtained results generally agree with data available for tundra soils (Dai et al 2001(Dai et al , 2002 and for podzolic and boggy-podzolic soils (Simpson et al 1997;Kechaikina et al 2011).…”

Section: Horizonsupporting

confidence: 81%

Humic substances elemental composition of selected taiga and tundra soils from Russian European North-East

Лодыгин¹,

Beznosikov²,

Abakumov³

2017

Polish Polar Research

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This paper provides an overview of the results of research on changes in ground temperature down to 50 cm depth, on the Kaffiøyra Plain, Spitsbergen in the summer seasons. To achieve this, measurement data were analysed from three different ecotopes (CALM Site P2A, P2B and P2C) -a beach, a moraine and tundra -collected during 22 polar expeditions between 1975 and 2014. To ensure comparability, data sets for the common period from 21 July to 31 August (referred to as the "summer season" further in the text) were analysed. The greatest influence on temperature across the inves− tigated ground layers comes from air temperature (correlation coefficients ranging from 0.61 to 0.84). For the purpose of the analysis of the changes in ground temperature in the years 1975-2014, missing data for certain summer seasons were reconstructed on the ba− sis of similar data from a meteorological station at Ny−Ålesund. The ground temperature at the Beach site demonstrated a statistically−significant growing trend: at depths from 1 to 10 cm the temperature increased by 0.27-0.28°C per decade, and from 20 to 50 cm by as much as 0.30°C per decade. On the Kaffiøyra Plain, the North Atlantic Oscillation (NAO) has a greater influence on the ground and air temperature than the Arctic Oscilla− tion (AO).

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Section: Horizonsupporting

confidence: 81%

Humic substances elemental composition of selected taiga and tundra soils from Russian European North-East

Лодыгин¹,

Beznosikov²,

Abakumov³

2017

Polish Polar Research

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“…For conciseness, detailed findings are given in this report for the HS obtained from the surface soil horizons of podzol profiles under oak and pine forests located in Ireland and England (Simpson 1999;Simpson et al 1997a). However, conclusions drawn here are consistent with experimental observations made on the full set of samples, and are made with reference to alkaline soluble humic materials.…”

Section: Methodsmentioning

confidence: 99%

“…After exhaustive extraction, the residual soil was effectively depleted of any dark coloration from organic matter. The organic extract was then isolated on XAD-8 resin (Simpson et al 1997a), and freeze-dried. The total yields from these procedures ranged between 10 and 30 g of organic matter per kilogram (air-dried soil).…”

Section: Methodsmentioning

confidence: 99%

Molecular structures and associations of humic substances in the terrestrial environment

Simpson

Kingery

Hayes

et al. 2002

Naturwissenschaften

249

161

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Here we show, for the first time, evidence of the primary molecular structures in humic substances (HS), the most abundant naturally occurring organic molecules on Earth, and their associations as mixtures in terrestrial systems. Multi-dimensional nuclear magnetic resonance (NMR) experiments show us that the major molecular structural components in the mixtures operationally defined as HS are aliphatic acids, ethers, esters and alcohols; aromatic lignin derived fragments; polysaccharides and polypeptides. By means of diffusion ordered spectroscopy, distinct diffusion coefficients consistent with relatively low molecular weight molecules were observed for all the components in the mixtures, and saccharides were the largest single class of component present. Liquid chromatography NMR confirmed that HS components can be easily separated and nuclear Overhauser effect (NOE) enhancements support the finding that the components are of relatively low molecular weight

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“…Detailed descriptions of the soil profile are given by Little (1994) The sequence of extracting solvents used was: water, 0.1 M sodium pyrophosphate (pH 7.0), 0.1 M sodium pyrophosphate (pH 10.6), and 0.1 M sodium pyrophosphate plus 0.1 M NaOH at pH 12.6. The humic and fulvic acids were isolated as described by Simpson et al (1997b) and fractionated using the XAD‐8 and XAD‐4 resins (Rohm and Haas, Philadelphia, PA) in tandem (Hayes, 1996; Malcolm et al, 1992; Simpson, 1999). The fulvic acid fraction isolated at pH 12.6 is the sample used in this study.…”

Section: Methodsmentioning

confidence: 99%

Improvements in the Two‐Dimensional Nuclear Magnetic Resonance Spectroscopy of Humic Substances

et al. 2002

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Understanding pollutant sorption, bioremediation of these pollutants, and their interactions with humic substances requires knowledge of molecular-level processes. New developments with nuclear magnetic resonance (NMR) experiments and labeled compounds have improved the overall understanding of these mechanisms. The advancements made with two-dimensional NMR show great promise, as structural information and hydrogen-carbon bond connectivity can be discerned. This communication presents the application of improved two-dimensional NMR methods, the double quantum filtered (DQF) correlation spectroscopy (COSY) and echo/anti-echo heteronuclear single quantum coherence (HSQC) experiments, for use in structural studies of humic substances. Both experiments were found to produce significant improvements over the conventional COSY and heteronuclear multiple quantum coherence (HMQC) experiments that have been previously employed in similar studies. The more sensitive echo/anti-echo HSQC experiment produced more cross-peaks with higher resolution when compared with the HMQC spectra. The DQF-COSY significantly suppressed the diagonal signals and allowed numerous signals previously hidden in the standard COSY experiment to be observed. These improvements will aid current characterization strategies of humic substances from soils, sediments, and water and their subsequent reactions with pollutants and microorganisms.

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Humic Substances from Podzols Under Oak Forest and a Cleared Forest Site I. Isolation and Characterization

Cited by 12 publications

References 4 publications

Humic substances elemental composition of selected taiga and tundra soils from Russian European North-East

Humic substances elemental composition of selected taiga and tundra soils from Russian European North-East

Molecular structures and associations of humic substances in the terrestrial environment

Improvements in the Two‐Dimensional Nuclear Magnetic Resonance Spectroscopy of Humic Substances

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