Navigation Links
First direct evidence that elemental fluorine occurs in nature
Date:7/5/2012

This release is available in German.

Fluorine is the most reactive chemical element. That is why it is not found in nature in its elemental form, but only in compounds, such as fluorite that was the accepted scientific doctrine so far. A special fluorite, the "fetid fluorite" or "antozonite", has been the subject of many discussions for nearly 200 years. This mineral emits an intensive odor when crushed. Now, for the first time, scientists from the Technische Universitaet Muenchen (TUM) and the Ludwig-Maximilians-University Munich (LMU) have successfully identified natural elemental fluorine in this fluorspar. They report their results in the international edition of the scientific journal Angewandte Chemie.

Being the most reactive of all chemical elements fluorine calls for extremely careful handling. It is so aggressive that glass laboratory instruments cannot resist it and even bricks burn when exposed to fluorine gas. Yet elemental fluorine has numerous industrial applications including corrosion prevention or fuel tank diffusion barriers and it is used for the production of sulphur hexafluoride, which serves as insulating material in high voltage switches.

Because of its extreme properties, until now chemists were convinced that fluorine cannot occur in nature in its elemental form, but only as a fluoride ion, for instance in minerals such as fluorite (CaF2), also known as fluorspar. A certain variety of it, the so-called "fetid fluorite" or "antozonite" from the "Maria" mine in Woelsendorf in the Upper Palatinate (Germany), has been an object of contention in science for some 200 years. When crushed, it emits an unpleasant, pungent smell.

A number of eminent chemists, among them Friedrich Woehler (1800-1882) and Justus von Liebig (1803-1873), proposed various substances to explain the odor. Over the years, scientists resorted to olfactory tests, chemical analyses and complex mass spectrometer studies coming to very different conclusions. Next to elemental fluorine, substances like iodine, ozone, phosphorus compounds, arsenic, sulphur, selenium, chlorine, hypochlorous acid and hydrofluorocarbons were made responsible for the smell. Direct evidence that this fluorspar has inclusions of fluorine and that the gas does not form during crushing was lacking hitherto.

Now, finally, a scientific team led by Florian Kraus, head of the Fluorine Chemistry Work Group at the Department of Chemistry of the Technische Universitaet Muenchen, and by Joern Schmedt auf der Guenne, head of the Emmy-Noether Work Group for Solid State NMR at the Department of Chemistry of the Ludwig-Maximilians-University Munich, have succeeded in directly proving the presence of fluorine in "antozonite" beyond any doubt. Using 19F-NMR spectroscopy, they were able to identify the fluorine "in-situ", i.e. non-destructively in its natural environment, and thereby put an end to the long discussions about the cause for the odor of "stinking fluorspar".

"It is not surprising that chemists doubted the existence of elemental fluorine in fetid fluorite," explain the researchers. "The fact that elemental fluorine and calcium, which would normally react with each other at once, are found here side by side is indeed hard to believe." However, in the case of "antozonite" there are very special conditions: The elemental fluorine is generated through minute uranium inclusions in the mineral, which constantly emit ionizing radiation and thus split the fluorite into calcium and elemental fluorine. The fluorine remains in minute inclusions, separated from the calcium by the non-reactive fluorite and thus retains its elemental form. The ionizing radiation also leads to the formation of calcium clusters, which give "antozonite" its dark color.


'/>"/>

Contact: Dr. Andreas Battenberg
battenberg@zv.tum.de
49-892-891-0510
Technische Universitaet Muenchen
Source:Eurekalert  

Related biology news :

1. Kessler Foundation implements Ekso Bionics first commercial robotic exoskeleton
2. Research reveals first evidence of hunting by prehistoric Ohioans
3. First model of how buds grow into leaves
4. American College of Rheumatology releases first classification criteria for polymyalagia rheumatica
5. Ottawa researchers to lead world-first clinical trial of stem cell therapy for septic shock
6. First complete full genetic map of promising energy crop
7. FirstMark Announces New Hire Jay Houtman as Southeast Regional Sales Manager
8. FirstMark Exhibiting at the Inaugural Atlanta Clinical Cardiology Update
9. New technology tracks sparrow migration for first time from California to Alaska
10. First mass extinction linked to marine anoxia
11. Scientists complete first-ever emperor penguin count from space
Post Your Comments:
*Name:
*Comment:
*Email:
Related Image:
First direct evidence that elemental fluorine occurs in nature
(Date:3/29/2016)... , March 29, 2016 ... "Company") LegacyXChange "LEGX" and SelectaDNA/CSI Protect are pleased to ... ink used in a variety of writing instruments, ensuring ... of originally created collectibles from athletes on LegacyXChange will ... analysis of the DNA. Bill Bollander ...
(Date:3/18/2016)... -- --> --> Competitive ... Unmanned Vehicles, Physical infrastructure and Perimeter Surveillance & Detection Systems ... security market and the continuing migration crisis in the ... has led visiongain to publish this unique report, which ... defence & security companies in the border security market ...
(Date:3/14/2016)... , Allemagne, March 14, 2016 ... ) - --> - Renvoi : image ... --> --> ... biométriques, fournit de nouveaux lecteurs d,empreintes digitales pour ... de DERMALOG sera utilisé pour produire des cartes ...
Breaking Biology News(10 mins):
(Date:4/29/2016)... ... April 29, 2016 , ... ... medicine, is excited to announce the launch of the Proove Health Foundation ... volunteerism, and education to promote the use of personalized medicine for tackling the ...
(Date:4/29/2016)... KY and San Diego, CA (PRWEB) , ... April 29, 2016 ... ... National Stem Cell Foundation (NSCF) to support the development of a patient-specific stem cell ... Dr. Andrés Bratt-Leal in the lab of Dr. Jeanne Loring at The Scripps Research ...
(Date:4/28/2016)... Q BioMed Inc. (OTCQB:QBIO), ...  was featured in an article he wrote on ... To Tread: http://www.lifescienceleader.com/doc/accelerators-enter-when-vcs-fear-to-tread-0001 ... an essential business journal for life science executives ... Big Pharmas. Their content is designed to inform ...
(Date:4/28/2016)... ... April 28, 2016 , ... Morris Midwest ( http://www.morrismidwest.com ... regional manufacturers at its Maple Grove, Minnesota technical center, May 11-12. The ... Trumpf. Almost 20 leading suppliers of tooling, accessories, software and other related ...
Breaking Biology Technology: