Abstract
The BCR sequential extraction procedure is widely used to determine the operational speciation of potentially toxic elements (PTE) in environmental solid samples (e.g. soils and sediments) in order to obtain information on their mobility, bioavailability and toxicity to organism. When applying the BCR sequential extraction procedure, a dichotomy exists between maintaining a sample’s natural speciation, and pre-treating the sample to make it stable and more suitable for standard laboratory operations such as sieving, cone-and-quartering etc. Sample drying in particular has been reported to cause redistribution of analytes to more readily extractable forms.
Pseudototal aqua regia digestion and BCR sequential extraction procedure were applied to sediments collected from the River Derwent and the River Wear, UK, both of which are impacted by historical mining and smelting. Sediments were analysed as received, freeze-dried and air-dried. Digests and extracts were analysed for As, Cd, Cu, Fe, Pb and Zn using an Agilent 7700x ICP-MS instrument.
It was found that freeze drying significantly transferred Cd, Fe, and Zn to forms inaccessible to aqua regia digestion. Different changes in operational speciation occurred for different PTE (at 95 % confidence level) but no sample pre-treatment procedure preserved the speciation of the PTE intact. Ecological risk values of Cd, Cu, Fe, Pb and Zn calculated using the risk assessment code also differed between treated samples and sediments as received. To obtain the most accurate information on operational speciation of PTE in freshwater sediment – and hence the most appropriate information to use in risk assessment – it is recommended that samples should be analysed immediately as received.
1.G. Rauret, J. F. Lopez-Sanchez, Sahuquillo A, Rubio R, Davidson C, Ure A and Quevauviller P, J. Environ. Monit., 1999, 1, 57 - 61.
2.E. Hiller and M. Sutriepka, J. Hydrol. Hydromech, 2008, 56, 45 -58.
3.T. Hjorth, Analytica Chimica Acta, 2004, 526, 95-102.
Pseudototal aqua regia digestion and BCR sequential extraction procedure were applied to sediments collected from the River Derwent and the River Wear, UK, both of which are impacted by historical mining and smelting. Sediments were analysed as received, freeze-dried and air-dried. Digests and extracts were analysed for As, Cd, Cu, Fe, Pb and Zn using an Agilent 7700x ICP-MS instrument.
It was found that freeze drying significantly transferred Cd, Fe, and Zn to forms inaccessible to aqua regia digestion. Different changes in operational speciation occurred for different PTE (at 95 % confidence level) but no sample pre-treatment procedure preserved the speciation of the PTE intact. Ecological risk values of Cd, Cu, Fe, Pb and Zn calculated using the risk assessment code also differed between treated samples and sediments as received. To obtain the most accurate information on operational speciation of PTE in freshwater sediment – and hence the most appropriate information to use in risk assessment – it is recommended that samples should be analysed immediately as received.
1.G. Rauret, J. F. Lopez-Sanchez, Sahuquillo A, Rubio R, Davidson C, Ure A and Quevauviller P, J. Environ. Monit., 1999, 1, 57 - 61.
2.E. Hiller and M. Sutriepka, J. Hydrol. Hydromech, 2008, 56, 45 -58.
3.T. Hjorth, Analytica Chimica Acta, 2004, 526, 95-102.
| Original language | English |
|---|---|
| Publication status | Published - 1 Jul 2019 |
| Event | 35th International Conference on Geochemistry and Health : SEGH 2019 - Manchester Metropolitan University, Manchester, United Kingdom Duration: 1 Jul 2019 → 5 Jul 2019 Conference number: 35 https://www2.mmu.ac.uk/segh-19/ https://segh.net/f/35th-international-conference-on-geochemistry-and-health |
Conference
| Conference | 35th International Conference on Geochemistry and Health |
|---|---|
| Country/Territory | United Kingdom |
| City | Manchester |
| Period | 1/07/19 → 5/07/19 |
| Internet address |
Keywords
- potentially toxic elements (PTE)
- environmentally solid samples
- freshwater sediments