The Isotopic Ratios of Boron in Coals

Abstract

Isotopic ratios of boron in typical 5 coals from Japan, Canada, China, South Africa and the U.S.A. have been measured with surface ionization mass spectrometry. The work was performed by obtaining the information about the origin of coals, e.g., marin or non-marin.
The results indicated that the ¹¹B/¹⁰B ratio in Taiheiyo Coal (Japan) was a high value of 4.177 which was similar to that in sea water, while the ratios in other 4 coals were lower values of 3.966~4.013. These facts suggest that Taiheiyo Coal deposited through contact with sea water, but others were not, probably contacted with ground water.
As a simulation for the equilibrium between sea water and coal, using activated charcoal, the isotopic fractionation factor was determined to be 1.022.
In the present work the gain of secondary electron mutiplier for the ion beam Na₂BO₂⁺ was cofirmed to be inversely proportional to the root of the ion mass.