| Full text | |
| Author(s): |
Total Authors: 3
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| Affiliation: | [1] Univ Campinas UNICAMP, Inst Geosci, Rua Carlos Gomes 250, BR-13108855 Campinas, SP - Brazil
Total Affiliations: 1
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| Document type: | Journal article |
| Source: | GEOSTANDARDS AND GEOANALYTICAL RESEARCH; v. 43, n. 1, p. 189-208, MAR 2019. |
| Web of Science Citations: | 4 |
| Abstract | |
The complete dissolution of representative test portions of powdered rock samples for the determination of the mass fractions of trace elements by ICP-MS relies either on aggressive and time-consuming acid digestions or fusion/sintering with appropriate fluxes. Here, we evaluate a microwave oven dissolution method that employs a solution of NH4HF2 and HNO3. The entire procedure occurs in a closed vessel system and takes up to 4 h. In hundreds of digestions, the precipitation of fluorides was never observed. Replicate decomposition of 100 mg of twenty-one international reference materials (RMs) of igneous rocks, and also one of a shale presented mostly satisfactory recoveries of forty-one trace elements. Important exceptions were Zr and Hf in G-2 and GSP-2 (mean recoveries of ca. 70%), although for four other felsic rock RMs, the digestion was complete. For ultramafic rock RMs, we present Cr results that indicate quantitative dissolution of Cr-bearing phases. We discuss the findings and conclude that advances in sample preparation of geological materials for instrumental analysis would benefit from a better understanding of how specific characteristics, such as composition and crystallinity of certain minerals, may affect their reactivity. (AU) | |
| FAPESP's process: | 18/07317-3 - 10th International Conference on the Analysis of Geological and Environmental Materials |
| Grantee: | Jacinta Enzweiler |
| Support Opportunities: | Research Grants - Meeting - Abroad |