Details
| Original language | English |
|---|---|
| Pages (from-to) | 351-363 |
| Number of pages | 13 |
| Journal | Geostandards and Geoanalytical Research |
| Volume | 40 |
| Issue number | 3 |
| Early online date | 23 Dec 2015 |
| Publication status | Published - 3 Sept 2016 |
Abstract
Fluorine plays an important role in magmatic and hydrothermal processes, but due to its low abundance in geological samples determining F is difficult by electron probe microanalysis. By using a W-Si multi-layered pseudocrystal as the diffraction crystal instead of thallium acid phthalate (TAP), count rates were considerably higher, which however introduced spectral interferences between FKα and FeLα and MgKβ lines when normal integral mode is applied. In this study, we developed a protocol using a W-Si multi-layered pseudocrystal for measuring accurately trace level F in both minerals and glasses. First, we used differential mode with an optimised PHA (pulse height analysis) setting in signal processing, instead of normal integral mode, which completely eliminated the second-order MgKβ line. Second, the overlap of the first-order FeLα on FKα peak, which cannot be filtered by modifying the PHA setting, was calibrated quantitatively using F-free minerals and silicate glasses. Applying this two-step method, F was determined in a number of reference glasses, as well as in glasses synthesised from powders of the rock reference materials AC-E, GS-N and DR-N. Our data are consistent within error with F concentrations determined by other methods, demonstrating the reliability of this method.
Keywords
- electron probe microanalysis, in situ techniques, microbeam techniques, reference materials, wavelength dispersive X-ray fluorescence spectrometry
ASJC Scopus subject areas
- Earth and Planetary Sciences(all)
- Geology
- Earth and Planetary Sciences(all)
- Geochemistry and Petrology
Cite this
- Standard
- Harvard
- Apa
- Vancouver
- BibTeX
- RIS
In: Geostandards and Geoanalytical Research, Vol. 40, No. 3, 03.09.2016, p. 351-363.
Research output: Contribution to journal › Article › Research › peer review
}
TY - JOUR
T1 - A Practical Method for Accurate Measurement of Trace Level Fluorine in Mg- and Fe-Bearing Minerals and Glasses Using Electron Probe Microanalysis
AU - Zhang, Chao
AU - Koepke, Jürgen
AU - Wang, Lian Xun
AU - Wolff, Paul Eric
AU - Wilke, Sören
AU - Stechern, André
AU - Almeev, Renat
AU - Holtz, Francois
N1 - Funding Information: We thank Michael Marks (Universit?t T?bingen) for providing rock powders of AC-E, GS-N and DR-N, Martin Oeser for providing BCR-2G, and Tim M?ller and Anna-Maria Welsch for helpful discussions. Special thanks go to Julian Feige for his perfect preparation of thin sections. This paper benefited greatly from critical and constructive comments of two anonymous reviewers and the journal editors. This work was supported by a ?Wege in die Forschung? project (granted by Leibniz Universit?t Hannover to Chao Zhang), DFG projects KO 1723/17 and HO 1337/31. Requests for the newly synthesised AC-E, GS-N and DR-N glasses as microanalytical reference materials can be addressed to the corresponding author.
PY - 2016/9/3
Y1 - 2016/9/3
N2 - Fluorine plays an important role in magmatic and hydrothermal processes, but due to its low abundance in geological samples determining F is difficult by electron probe microanalysis. By using a W-Si multi-layered pseudocrystal as the diffraction crystal instead of thallium acid phthalate (TAP), count rates were considerably higher, which however introduced spectral interferences between FKα and FeLα and MgKβ lines when normal integral mode is applied. In this study, we developed a protocol using a W-Si multi-layered pseudocrystal for measuring accurately trace level F in both minerals and glasses. First, we used differential mode with an optimised PHA (pulse height analysis) setting in signal processing, instead of normal integral mode, which completely eliminated the second-order MgKβ line. Second, the overlap of the first-order FeLα on FKα peak, which cannot be filtered by modifying the PHA setting, was calibrated quantitatively using F-free minerals and silicate glasses. Applying this two-step method, F was determined in a number of reference glasses, as well as in glasses synthesised from powders of the rock reference materials AC-E, GS-N and DR-N. Our data are consistent within error with F concentrations determined by other methods, demonstrating the reliability of this method.
AB - Fluorine plays an important role in magmatic and hydrothermal processes, but due to its low abundance in geological samples determining F is difficult by electron probe microanalysis. By using a W-Si multi-layered pseudocrystal as the diffraction crystal instead of thallium acid phthalate (TAP), count rates were considerably higher, which however introduced spectral interferences between FKα and FeLα and MgKβ lines when normal integral mode is applied. In this study, we developed a protocol using a W-Si multi-layered pseudocrystal for measuring accurately trace level F in both minerals and glasses. First, we used differential mode with an optimised PHA (pulse height analysis) setting in signal processing, instead of normal integral mode, which completely eliminated the second-order MgKβ line. Second, the overlap of the first-order FeLα on FKα peak, which cannot be filtered by modifying the PHA setting, was calibrated quantitatively using F-free minerals and silicate glasses. Applying this two-step method, F was determined in a number of reference glasses, as well as in glasses synthesised from powders of the rock reference materials AC-E, GS-N and DR-N. Our data are consistent within error with F concentrations determined by other methods, demonstrating the reliability of this method.
KW - electron probe microanalysis
KW - in situ techniques
KW - microbeam techniques
KW - reference materials
KW - wavelength dispersive X-ray fluorescence spectrometry
UR - http://www.scopus.com/inward/record.url?scp=84955572337&partnerID=8YFLogxK
U2 - 10.1111/j.1751-908x.2015.00390.x
DO - 10.1111/j.1751-908x.2015.00390.x
M3 - Article
AN - SCOPUS:84955572337
VL - 40
SP - 351
EP - 363
JO - Geostandards and Geoanalytical Research
JF - Geostandards and Geoanalytical Research
SN - 1639-4488
IS - 3
ER -