Lability of copper bound to humic acid
Geochemical speciation models generally include the assumption that all metal bound to humic acid and fulvic acid (HA, FA) is labile. However, in the current study, we determined the presence of a soluble ‘non-labile’ Cu fraction bound to HA extracted from grassland and peat soils. This was quantif...
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| Format: | Article |
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Elsevier
2015
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| Online Access: | https://eprints.nottingham.ac.uk/28778/ |
| _version_ | 1848793640115109888 |
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| author | Mao, Lingchen Young, Scott D. Bailey, Liz |
| author_facet | Mao, Lingchen Young, Scott D. Bailey, Liz |
| author_sort | Mao, Lingchen |
| building | Nottingham Research Data Repository |
| collection | Online Access |
| description | Geochemical speciation models generally include the assumption that all metal bound to humic acid and fulvic acid (HA, FA) is labile. However, in the current study, we determined the presence of a soluble ‘non-labile’ Cu fraction bound to HA extracted from grassland and peat soils. This was quantified by determining isotopically-exchangeable Cu (E-value) and EDTA-extraction of HA-bound Cu, separated by size-exclusion chromatography (SEC) and assayed by coupled ICP-MS. Evidence of time-dependent Cu fixation by HA was found during the course of an incubation study (160 days); up to 50% of dissolved HA-bound Cu was not isotopically exchangeable. This result was supported by extraction with EDTA where approximately 40% of Cu remained bound to HA despite dissolution in 0.05 M Na2-EDTA. The presence of a substantial non-labile metal fraction held by HA challenges the assumption of wholly reversible equilibrium which is central to current geochemical models of metal binding to humic substances. |
| first_indexed | 2025-11-14T19:03:30Z |
| format | Article |
| id | nottingham-28778 |
| institution | University of Nottingham Malaysia Campus |
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| last_indexed | 2025-11-14T19:03:30Z |
| publishDate | 2015 |
| publisher | Elsevier |
| recordtype | eprints |
| repository_type | Digital Repository |
| spelling | nottingham-287782020-05-04T17:09:21Z https://eprints.nottingham.ac.uk/28778/ Lability of copper bound to humic acid Mao, Lingchen Young, Scott D. Bailey, Liz Geochemical speciation models generally include the assumption that all metal bound to humic acid and fulvic acid (HA, FA) is labile. However, in the current study, we determined the presence of a soluble ‘non-labile’ Cu fraction bound to HA extracted from grassland and peat soils. This was quantified by determining isotopically-exchangeable Cu (E-value) and EDTA-extraction of HA-bound Cu, separated by size-exclusion chromatography (SEC) and assayed by coupled ICP-MS. Evidence of time-dependent Cu fixation by HA was found during the course of an incubation study (160 days); up to 50% of dissolved HA-bound Cu was not isotopically exchangeable. This result was supported by extraction with EDTA where approximately 40% of Cu remained bound to HA despite dissolution in 0.05 M Na2-EDTA. The presence of a substantial non-labile metal fraction held by HA challenges the assumption of wholly reversible equilibrium which is central to current geochemical models of metal binding to humic substances. Elsevier 2015-07-01 Article PeerReviewed Mao, Lingchen, Young, Scott D. and Bailey, Liz (2015) Lability of copper bound to humic acid. Chemosphere, 131 . pp. 201-208. ISSN 0045-6535 Humic acid Non-labile metal WHAM model Isotopic dilution EDTA extraction SEC-ICP-MS http://www.sciencedirect.com/science/article/pii/S0045653515002453 doi:10.1016/j.chemosphere.2015.03.035 doi:10.1016/j.chemosphere.2015.03.035 |
| spellingShingle | Humic acid Non-labile metal WHAM model Isotopic dilution EDTA extraction SEC-ICP-MS Mao, Lingchen Young, Scott D. Bailey, Liz Lability of copper bound to humic acid |
| title | Lability of copper bound to humic acid |
| title_full | Lability of copper bound to humic acid |
| title_fullStr | Lability of copper bound to humic acid |
| title_full_unstemmed | Lability of copper bound to humic acid |
| title_short | Lability of copper bound to humic acid |
| title_sort | lability of copper bound to humic acid |
| topic | Humic acid Non-labile metal WHAM model Isotopic dilution EDTA extraction SEC-ICP-MS |
| url | https://eprints.nottingham.ac.uk/28778/ https://eprints.nottingham.ac.uk/28778/ https://eprints.nottingham.ac.uk/28778/ |