Affiliation:
1. National University of Science and Technology “MISiS”
2. National University of Science and Technology “MISiS”; Vernadsky Institute of Geochemistry and Analytical Chemistry, Russian Academy of Sciences
3. Lomonosov Moscow State University, Faculty of Chemistry
4. National University of Science and Technology “MISiS”; The Institute of Microelectronics Technology and High Purity Materials, Russian Academy of Sciences
Abstract
Sequential extraction procedures (SEP) have been widely used for the fractionation of trace elements in soils according to their physicochemical mobility and bioaccessibility. Potassium/sodium pyrophosphate in alkaline medium may be considered as the most appropriate extracting reagent for the recovery of amorphous metal-organic complexes, which play a very important role in biological, physical, and chemical processes in soil. However, the selectivity of pyrophosphate has been poorly studied. In the present work the ability of pyrophosphate to attack mineral inorganic phases of environmental solids was assessed using dynamic extraction, which allows one to minimize artifacts and mimic natural conditions. Samples of gabbro and granite containing nearly no organic compounds were taken as example. The eluents applied addressed exchangeable, specifically sorbed, bound to Mn oxides, and bound to metal-organic complexes fractions extractable by 0.05 M Ca(NO3)2, 0.43 M CH3COOH, 0.1 M NH2OH · HCl, and 0.1 M K4P2O7 at pH 11, respectively. As expected, pyrophosphate extraction leads to a partial dissolution of elements bound to inorganic compounds. The recovery of aluminum, iron, manganese, and rare earth elements by pyrophosphate is up to 4% of their total concentrations in samples. The results were discussed on the basis of coordination chemistry of pyrophosphate complexes. In general, pyrophosphate extraction could be further regarded to be sufficiently selective for the dissolution of metal-organic complexes while using SEP in environmental analysis, soil science, and biogeochemistry. Nevertheless, in the interpretation of the fractionation results, a partial dissolution of mineral inorganic phases should be taken into consideration, especially for soils with low content of organic compounds.
Cited by
1 articles.
订阅此论文施引文献
订阅此论文施引文献,注册后可以免费订阅5篇论文的施引文献,订阅后可以查看论文全部施引文献