2. Determining the chemical forms of elements
2.1 Definitions
There are two main types of method for understanding the distribution of trace elements ("fractionation"): physical (or direct) methods and chemical (or indirect) methods. In the case of physical methods, the fractionation of the element in question is approached directly, using non-destructive analytical means in the sense that the structure containing or sorbing the element is not modified. In the case of chemical methods, the element is taken out of its structural context by chemical...
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Determining the chemical forms of elements
Example of extraction diagrams and their use
Bibliography
References
Appendix 1 Sequential extraction procedure (BCR scheme) for metal fractionation in sediments and soils
1.Instruments and reagents
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Devices
The laboratory equipment used may be made of borosilicate glass, poly6Fethylene, polypropylene or PTFE, with the exception of the centri6Ffugation tube, which must be made of borosilicate glass or PTFE. Clean vials in contact with samples or...
Appendix 2 Single extraction procedures for metal fractionation in soils
Unique extraction procedures for soil analysis (see paragraph 4.3.3. ) based on EDTA 0.05 mol/L and acetic acid 0.43 mol/L are described below.
Extractions should be performed in borosilicate glass, polyethylene, polypropylene or PTFE bottles, using an inverting shaker. Laboratory equipment should be cleaned with 4 mol/L...
Appendix 3 SMT protocol for the fractionation of phosphorus forms in freshwater sediments
1.Reagents and equipment
The reagents used are HCl 1 mol/L, HCl 3.5 mol/L, NaOH 1 mol/L and NaCl 1 mol/L. The laboratory equipment used can be made of polyethylene or polypropylene, including centrifuge tubes. Stirrers can be magnetic stirrers, stirring tables or inverting stirrers.
All reagents must be at least...
Standardization
Association française de normalisation AFNOR
- Sécurité des jouets - Partie 3 : migration de certains éléments (Indice de classement : S51-214). - NF EN 71-3 - 03-95
- Qualité du sol - Extraction des éléments en traces solubles dans l'eau régale (Indice de classement : X31-415). - NF ISO 11466 - 06-95
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