&lt;sup&gt;13&lt;/sup&gt;C NMR並びに高速サイズ排除クロマトグラフィーによる土壌腐植酸の特徴付け

Fujitake, Nobuhide; Asakawa, Daichi; Yanagi, Yukiko

doi:10.2116/bunsekikagaku.61.287

Cited by 10 publications

(12 citation statements)

References 19 publications

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“…For nonionic pesticides, hydrophobic bonding (partitioning) is most common, but other possible mechanisms for sorption by HS include charge‐transfer complexes, covalent bonding, hydrogen bonding, and Van der Waals attractions (Senesi and Chen, 1989; Senesi, 1992). Bonding mechanisms commonly observed for ionizable pesticides and HS include charge‐transfer (electron donor–acceptor) complexes, hydrogen bonding, ligand exchange, and Van der Waals attractions (Fusi et al, 1988; Senesi and Chen, 1989; Hermosin and Cornejo, 1993; Piccolo and Celano, 1994; Senesi et al, 1995, 1997; Ferreira et al, 2002; Sheals et al, 2002).…”

Section: Modeling Of Metal Ion Binding In Soilsmentioning

confidence: 99%

Environmental and Agricultural Relevance of Humic Fractions Extracted by Alkali from Soils and Natural Waters

et al. 2019

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To study the structure and function of soil organic matter, soil scientists have performed alkali extractions for soil humic acid (HA) and fulvic acid (FA) fractions for more than 200 years. Over the last few decades aquatic scientists have used similar fractions of dissolved organic matter, extracted by resin adsorption followed by alkali desorption. Critics have claimed that alkaliextractable fractions are laboratory artifacts, hence unsuitable for studying natural organic matter structure and function in field conditions. In response, this review first addresses specific conceptual concerns about humic fractions. Then we discuss several case studies in which HA and FA were extracted from soils, waters, and organic materials to address meaningful problems across diverse research settings. Specifically, one case study demonstrated the importance of humic substances for understanding transport and bioavailability of persistent organic pollutants. An understanding of metal binding sites in FA and HA proved essential to accurately model metal ion behavior in soil and water. In landscape-based studies, pesticides were preferentially bound to HA, reducing their mobility. Compost maturity and acceptability of other organic waste for land application were well evaluated by properties of HA extracted from these materials. A young humic fraction helped understand N cycling in paddy rice (Oryza sativa L.) soils, leading to improved rice management. The HA and FA fractions accurately represent natural organic matter across multiple environments, source materials, and research objectives. Studying them can help resolve important scientific and practical issues.

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Section: Modeling Of Metal Ion Binding In Soilsmentioning

confidence: 99%

Environmental and Agricultural Relevance of Humic Fractions Extracted by Alkali from Soils and Natural Waters

et al. 2019

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“…The mean Mw of HAs obtained was 13693 Da (SD ¼ 11949 Da) from the same soil samples (n ¼ 33) by Fujitake et al (2012) using the same analytical…”

Section: Weight-averaged Molecular Weight and Elemental Compositionmentioning

confidence: 99%

“…Liquid state 13 C NMR spectra Fujitake et al (2012) reported the composition of the C functional groups in soil HAs (n ¼ 33) investigated by 13 C NMR with the same method as in this study. They found that the carboxyl C, O-alkyl C, and alkyl C contents were 18.4% (SD ¼ 2.0%), 20.7% (SD ¼ 7.5%) and 16.2% (SD ¼ 7.5%), respectively.…”

Section: Weight-averaged Molecular Weight and Elemental Compositionmentioning

confidence: 99%

Characterization of DAX‐8 adsorbed soil fulvic acid fractions by various types of analyses

Iimura¹,

Ohtani²,

Chersich³

et al. 2012

Soil Science and Plant Nutrition

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We investigated the optical absorption properties (A 400 /C and A 600 /C values), elemental composition, weightaveraged molecular weight (Mw), and liquid-state carbon-13 ( 13 C) nuclear magnetic resonance (NMR) spectroscopy of DAX-8 adsorbed fulvic acid fractions (DAX-8 FAs) in various soils (n ¼ 36) to establish the general trends in their chemical characteristics. We also compared our results with those of humic acids (HAs) obtained from the same soils used in this study and other published data to discuss the differences between them. Our results clearly indicate that DAX-8 FAs with high carboxyl C content have small Mw and low hydrogen to carbon (H/C) ratio. In addition, DAX-8 FAs with high carbonyl C and alkyl C content have high A 400 /C values and H/C ratios, respectively. These results strongly suggest that DAX-8 FAs with high aliphatic chemical properties have low carboxyl C content, large Mw and high H/C ratio. There are significant differences in chemical characteristics among the various soil types in almost all data; e.g., DAX-8 FAs from Podzols showed significantly higher A 400 /C values, larger Mw, higher carbonyl C and O-aryl C content than those obtained from Andosols. However, these two C functional groups are relatively low values in the total C content among all soil types, suggesting that DAX-8 FAs may exhibit only small differences in chemical properties among the various soil types. The comparison with published data regarding soil HAs shows that DAX-8 FAs are characterized by smaller Mw; lower C, H, and nitrogen (N)

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“…All HA samples for the HA-groundwater resuspension experiments described below were stored frozen at −5 °C. HA characterization data were previously reported elsewhere 16 and on IHSS website ( http://humic-substances.org/13c-nmr-estimates-of-carbon-distribution-in-ihss-samples/ ).…”

Section: Methodsmentioning

confidence: 99%

“…The HAs were characterized by 13 C nuclear magnetic resonance (NMR) spectroscopy. The wide range of organic matter sources (biota) and various weathering conditions resulted in different molecular and elemental compositions of purified HAs, with contrasting organic C and N abundance (e.g., N varying from 1.10% to 6.59%) and compositions (e.g., carboxylate functional group abundance varying from 13% to 21) 16 . After the resuspension of purified HAs in artificial groundwater amended with different radionuclides, partitioning coefficients (K d ) of different radionuclides and their activity percentage were measured in the particulate (>0.45 µm), colloidal (3 kDa to 0.45 µm) and truly dissolved (<3 kDa) fractions of the HA-groundwater slurry.…”

Section: Introductionmentioning

confidence: 99%

Radionuclide uptake by colloidal and particulate humic acids obtained from 14 soils collected worldwide

Lin

Wang

et al. 2018

Sci Rep

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Uptake of six particle-reactive and/or redox-sensitive radionuclides (210Pb, 234Th, 7Be, 59Fe, 237Np and 233Pa) by 14 humic acids (HAs) was investigated in artificial groundwater under mildly acidic conditions (pH~5.5). In HA-groundwater slurry, Pb, Be, Fe and Pa bound strongly to particulate HA (>0.45 µm), supporting their application as tracers of soil erosion. Th bound strongly to the colloidal HA (3 kDa-0.45 µm) and as such, would not be a good candidate as a tracer for monitoring soil erosion. HAs likely reduced the oxidized neptunyl form (Np(V)O4+) to Np(IV) based on its enhanced particle-reactivity and Np uptake by particulate HAs, partially retarding the movement of anthropogenic 237Np in field polluted environments. Particulate/colloidal carbonyl/O-aryl (likely through hydroquinone/quinone) functionalities in the HA correlated to Np and Pa uptake, but only particulate O-aryl functionalities was responsible for Fe uptake. The carboxylate- and carbonyl/O-aryl-containing organic functionalities in the HA correlated strongly with Th uptake. In contrast, no significant correlations between organic parameters and Pb or Be uptake implied their predominance of uniform surface adsorption onto particles. This study provides novel insight into the binding of six radionuclides with different organic functionalities of three size fractions, as well as its possible impact on their application in the soil-tracing research.

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<sup>13</sup>C NMR並びに高速サイズ排除クロマトグラフィーによる土壌腐植酸の特徴付け

Cited by 10 publications

References 19 publications

Environmental and Agricultural Relevance of Humic Fractions Extracted by Alkali from Soils and Natural Waters

Environmental and Agricultural Relevance of Humic Fractions Extracted by Alkali from Soils and Natural Waters

Characterization of DAX‐8 adsorbed soil fulvic acid fractions by various types of analyses

Radionuclide uptake by colloidal and particulate humic acids obtained from 14 soils collected worldwide

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