Determination of Li Abundances in Chondrules, Bulk Chondrites, and Standard Rocks by Direct-Loading Isotope Dilution Mass Spectrometry

Abstract

Precise isotope dilution technique of Li, along with other alkalis, alkaline earths and iron, for tiny silicate materials (having as low as 10 pg Li) is described. Samples were decomposed by acids, equilibrated with mixed spikes including ⁶Li and directly loaded on a mass spectrometer filament without chemical separation. Li and other lithophiles were measured by successive heating procedures. Results of precise Li analyses are presented for 7 Allende chondrules, 5 bulk chondrites and three standard rocks, JB-1, JB-2, and BCR-1.