Effects of sample drying on element forms in lake sediments
| Autor: | Gwendy E.M. Hall, J.E. Vaive, Kevin Telmer, Deborah A. Kliza-Petelle, Graeme F. Bonham-Carter, Pierre Pelchat |
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| Rok vydání: | 2006 |
| Předmět: | |
| Zdroj: | Geochemistry: Exploration, Environment, Analysis. 6:163-177 |
| ISSN: | 2041-4943 1467-7873 |
| DOI: | 10.1144/1467-7873/05-091 |
| Popis: | The application of a sequential extraction scheme provides information on the phase association of elements in a sample, such phases being described, for example, as ‘exchangeable/adsorbed’, ‘amorphous Fe/Al oxides’ and ‘soluble organics’. It is therefore critical to maintain the chemistry of a sample from the time of collection to its analysis and during its preparation for analysis. This paper focuses on the redistribution of elements, amongst five operationally defined phases, that occurs on air-drying of the sample; the effect of subsequent storage of the sample is not addressed. Two lake sediment cores (‘Green Lake’, 31 cm, and ‘Gravel Pit Lake’, 19 cm) were sampled at 1-cm intervals and divided into two sets immediately prior to sequential leach analysis of the ‘wet’ sample. The other set was air-dried prior to sequential leach analysis. Most of the 39 elements determined in the Green Lake sediment showed, on drying, a redistribution to more labile forms. For example, increases in Fe concentration in the oxide phases were observed with a concomitant decrease in the crystalline forms of Fe reporting to the final aqua regia digestion. These changes are generally small in magnitude ( |
| Databáze: | OpenAIRE |
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