Using isotopic dilution to assess chemical extraction of labile Ni, Cu, Zn, Cd and Pb in soils
Chemical extractants used to measure labile soil metal must ideally select for and solubilise the labile fraction, with minimal solubilisation of non-labile metal. We assessed four extractants (0.43 M HNO3, 0.43 M CH3COOH, 0.05 M Na2H2EDTA and 1 M CaCl2) against these requirements. For soils contami...
| Main Authors: | , , , , |
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| Format: | Article |
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Elsevier
2016
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| Online Access: | https://eprints.nottingham.ac.uk/33238/ |
| _version_ | 1848794590995283968 |
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| author | Garforth, Judith M. Bailey, Elizabeth H. Tye, Andrew M. Young, Scott D. Lofts, Stephen |
| author_facet | Garforth, Judith M. Bailey, Elizabeth H. Tye, Andrew M. Young, Scott D. Lofts, Stephen |
| author_sort | Garforth, Judith M. |
| building | Nottingham Research Data Repository |
| collection | Online Access |
| description | Chemical extractants used to measure labile soil metal must ideally select for and solubilise the labile fraction, with minimal solubilisation of non-labile metal. We assessed four extractants (0.43 M HNO3, 0.43 M CH3COOH, 0.05 M Na2H2EDTA and 1 M CaCl2) against these requirements. For soils contaminated by contrasting sources, we compared isotopically exchangeable Ni, Cu, Zn, Cd and Pb (EValue, mg kg-1), with the concentrations of metal solubilised by the chemical extractants (MExt, mg kg-1). Crucially, we also determined isotopically exchangeable metal in the soil–extractant systems (EExt, mg kg-1). Thus ‘EExt - EValue’ quantifies the concentration of mobilised non-labile metal, while ‘EExt - MExt’ represents adsorbed labile metal in the presence of the extractant. Extraction with CaCl2 consistently underestimated EValue for Ni, Cu, Zn and Pb, while providing a reasonable estimate of EValue for Cd. In contrast, extraction with HNO3 both consistently mobilised non-labile metal and overestimated the EValue. Extraction with CH3COOH appeared to provide a good estimate of EValue for Cd; however, this was the net outcome of incomplete solubilisation of labile metal, and concurrent mobilisation of non-labile metal by the extractant (MExt < EExt > EValue). The Na2H2EDTA extractant mobilised some non-labile metal in three of the four soils, but consistently solubilised the entire labile fraction for all soil-metal combinations (MExt ≈ EExt). Comparison of EValue, MExt and EExt provides a rigorous means of assessing the underlying action of soil chemical extraction methods and could be used to refine long-standing soil extraction methodologies. |
| first_indexed | 2025-11-14T19:18:37Z |
| format | Article |
| id | nottingham-33238 |
| institution | University of Nottingham Malaysia Campus |
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| last_indexed | 2025-11-14T19:18:37Z |
| publishDate | 2016 |
| publisher | Elsevier |
| recordtype | eprints |
| repository_type | Digital Repository |
| spelling | nottingham-332382020-05-04T20:01:59Z https://eprints.nottingham.ac.uk/33238/ Using isotopic dilution to assess chemical extraction of labile Ni, Cu, Zn, Cd and Pb in soils Garforth, Judith M. Bailey, Elizabeth H. Tye, Andrew M. Young, Scott D. Lofts, Stephen Chemical extractants used to measure labile soil metal must ideally select for and solubilise the labile fraction, with minimal solubilisation of non-labile metal. We assessed four extractants (0.43 M HNO3, 0.43 M CH3COOH, 0.05 M Na2H2EDTA and 1 M CaCl2) against these requirements. For soils contaminated by contrasting sources, we compared isotopically exchangeable Ni, Cu, Zn, Cd and Pb (EValue, mg kg-1), with the concentrations of metal solubilised by the chemical extractants (MExt, mg kg-1). Crucially, we also determined isotopically exchangeable metal in the soil–extractant systems (EExt, mg kg-1). Thus ‘EExt - EValue’ quantifies the concentration of mobilised non-labile metal, while ‘EExt - MExt’ represents adsorbed labile metal in the presence of the extractant. Extraction with CaCl2 consistently underestimated EValue for Ni, Cu, Zn and Pb, while providing a reasonable estimate of EValue for Cd. In contrast, extraction with HNO3 both consistently mobilised non-labile metal and overestimated the EValue. Extraction with CH3COOH appeared to provide a good estimate of EValue for Cd; however, this was the net outcome of incomplete solubilisation of labile metal, and concurrent mobilisation of non-labile metal by the extractant (MExt < EExt > EValue). The Na2H2EDTA extractant mobilised some non-labile metal in three of the four soils, but consistently solubilised the entire labile fraction for all soil-metal combinations (MExt ≈ EExt). Comparison of EValue, MExt and EExt provides a rigorous means of assessing the underlying action of soil chemical extraction methods and could be used to refine long-standing soil extraction methodologies. Elsevier 2016-07 Article PeerReviewed Garforth, Judith M., Bailey, Elizabeth H., Tye, Andrew M., Young, Scott D. and Lofts, Stephen (2016) Using isotopic dilution to assess chemical extraction of labile Ni, Cu, Zn, Cd and Pb in soils. Chemosphere, 155 . pp. 534-541. ISSN 1879-1298 http://www.sciencedirect.com/science/article/pii/S0045653516305860 doi:10.1016/j.chemosphere.2016.04.096 doi:10.1016/j.chemosphere.2016.04.096 |
| spellingShingle | Garforth, Judith M. Bailey, Elizabeth H. Tye, Andrew M. Young, Scott D. Lofts, Stephen Using isotopic dilution to assess chemical extraction of labile Ni, Cu, Zn, Cd and Pb in soils |
| title | Using isotopic dilution to assess chemical extraction of labile Ni, Cu, Zn, Cd and Pb in soils |
| title_full | Using isotopic dilution to assess chemical extraction of labile Ni, Cu, Zn, Cd and Pb in soils |
| title_fullStr | Using isotopic dilution to assess chemical extraction of labile Ni, Cu, Zn, Cd and Pb in soils |
| title_full_unstemmed | Using isotopic dilution to assess chemical extraction of labile Ni, Cu, Zn, Cd and Pb in soils |
| title_short | Using isotopic dilution to assess chemical extraction of labile Ni, Cu, Zn, Cd and Pb in soils |
| title_sort | using isotopic dilution to assess chemical extraction of labile ni, cu, zn, cd and pb in soils |
| url | https://eprints.nottingham.ac.uk/33238/ https://eprints.nottingham.ac.uk/33238/ https://eprints.nottingham.ac.uk/33238/ |