ISOTOPE GEOCHEMISTRY OF BORON
The atomic weight of boron and the possible existence of natural variations in its isotopic composition are both matters of active controversy. This controversy seems to stem, in part, from the fact that several investigators have used boron trifluoride as a radium for massspectrometric analysis. Boron trifluoride is unsuitable for this purpose because it is capable of reacting with many of the components of a mass spectrometer. In order to avoid such reactions, methyl borate, the methanol ester of boric acid, was chosen for the mass- spectrometric analyses in this investigation. Boron isotope analyses were conducted on twelve samples of methyl borate in a 12-inch, 60 deg , single- focusing mass spectrometer. The samples were prepared from material obtained from a variety of geological environments in the hope that they would reflect the extent of natural variation in the isotopic composition of boron. The composition of the boron in the samples investigated was found to be constant within the limits of experi mental error. Any natural variation which exists in these samples must be less than 1.5%. Fragmentation of hydrogens from the methyl borate molecule in the mass spectrometer necessitates complex corrections to make it possible to obtain the absolute abundance ratio of the isotopes. The ratio B/ sup 11//B/sup 10/ was determined to be 4.05 plus or minus 0.10, a value which substantiates those obtained by several recent investigators.
- Research Organization:
- Univ. of Texas, Austin
- NSA Number:
- NSA-16-023537
- OSTI ID:
- 4821398
- Journal Information:
- Dissertation Abstr., Vol. Vol: 22; Other Information: Orig. Receipt Date: 31-DEC-62
- Country of Publication:
- Country unknown/Code not available
- Language:
- English
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