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Instituto Venezolano De Investigaciones Cientificas Natural Radiocarbon Measurements IV

Published online by Cambridge University Press:  18 July 2016

M. A. Tamers
M. A. Tamers*
Affiliation:
Instituto Venezolano de Investigaciones Científicas, Department of Chemistry, Caracas, Venezuela
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The laboratory renewed operations in January, 1968 after a year's inactivity due to the absence of the head, who was on leave at the University of Bonn. Synthesized benzene continues as the dating medium, but various improvements have been made on the chemical method in order to increase capacity. Combustions are no longer carried out for normal materials. Instead, charcoal samples are used directly (after the usual pretreatment) and wood, plants, cloth, etc. are carbonized in a nitrogen atmosphere. Charring is a considerably more rapid procedure than combustion since it eliminates the CO2 collection, carbonate precipitation, and filtration steps. The charcoal then is reacted with molten lithium metal. Also, it was found that carbonates are attacked directly by hot lithium to produce carbides and the preliminary generation of CO2 gas is not indispensable. The carbide, cooled to room temperature, is reacted with old water (IVIC-317, Radiocarbon, 1967, v. 9, p. 240), the acetylene separated from hydrogen in a double liquid nitrogen-cooled trap, and benzene produced with a chromium activated silica-alumina catalyst.

Type
Research Article
Information
Radiocarbon , Volume 11 , Issue 2 , 1969 , pp. 396 - 422
Copyright
Copyright © The American Journal of Science 

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