Determination of lithium and halogens and the significance of lithium to the understanding of cosmochemical processes

With a newly developed method fluorine and the other halogens have been measured in terrestrial, meteoritic and lunar samples. As a valuable byproduct lithium was determined also via teh reactions⁶Li (n,α)t→¹⁶O (t, n)¹⁸F. From our measurements the following new values for the “cosmic” abundance are derived (in atoms per 10⁶ Si atoms) F 750, Cl 4350, Br 8.83, and I 1.14. We could show that the Li/Be or Li/Zr ratios can be used to estimate the ratio of the Mg-silicates to the group of refractory elements and in course to calculate the bulk composition of the Moon and other planetary objects.