Raman and FTIR spectroscopy applied to the conservation report of paleontological collections: identification of Raman and FTIR signatures of several iron sulfate species such as ferrinatrite and sideronatrite
| Autor: | Hugues Badet, Bertrand Lavédrine, Véronique Rouchon, Oulfa Belhadj, Serge Miska, Jean-Guy Michard, Olivier Bonnerot |
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| Rok vydání: | 2012 |
| Předmět: |
chemistry.chemical_classification
Sulfide Chemistry Inorganic chemistry Epsomite Infrared spectroscopy Iron sulfide 02 engineering and technology 010502 geochemistry & geophysics 021001 nanoscience & nanotechnology 01 natural sciences chemistry.chemical_compound symbols.namesake Iron sulfate Halotrichite symbols General Materials Science Sulfate 0210 nano-technology Raman spectroscopy Spectroscopy 0105 earth and related environmental sciences |
| Zdroj: | Journal of Raman Spectroscopy. 43:1265-1274 |
| ISSN: | 0377-0486 |
| Popis: | Fossil materials that contain iron sulfide are well known for their instability when exposed to oxygen and humidity. This term however combines a great variety of materials showing different types of damages. Most of them consist of crystal efflorescence appearing on the surface and inside the matrix. In this work, a methodology was determined for the analysis of these damages by the use of Raman and infrared spectroscopy. The infrared and Raman signatures of a large set of iron sulfates were characterized. Specific attention was paid to sideronatrite and ferrinatrite, which are two associated sodium/iron(III) sulfates, and their infrared and Raman bands were partially assigned. Analysis performed on a selection of 11 damaged fossils showed a great variety of degradation products: besides one case that appeared to be a synthetic resin close to polyvinylchloride acetate, which was applied with a brush on the fossil surface, all degradation products belong to the sulfate group. However, many iron-free sulfates, such as gypsum, halotrichite, epsomite, or pentahydrite were found, often in association with iron sulfates. In one case, despite the presence of iron in the matrix, no iron sulfate could be detected. This shows that the term ‘pyritic fossil’, commonly used by collection managers, is not appropriate as it oversimplifies the reality. A name such as ‘sulfide-containing fossil’ would be more suitable. Copyright © 2012 John Wiley & Sons, Ltd. |
| Databáze: | OpenAIRE |
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