On the Measurement of the Isotope Ratio of Potassium.

Abstract

A mass-spectrometric study has been carried out on the measurements of the isotopic ratio of potassium using a surface ionization ion source.The pretreatment of the sample filaments for removing background potassium was studied using enriched ⁴¹K isotope(96%)on rhenium, tantalum and tungsten filaments. Chloride, nitrate and sulfate of potassium were examined as a sample material for the measurement of isotopic ratios. Time variations of ³⁹K/⁴¹K ratio during one run were observed with potassium chloride and potassium iodide samples and the isotope fractionation effect in the ion source was studied. Among these compounds, potassium iodide was most preferable one as a sample material because of the large ionizing efficiency and of the small isotope fractionation.