Isotopic Analysis of Lead by Tetramethyl Lead Method

Abstract

In connection with the age determination of geologic samples, an attempt was made to improve the tetramethyl lead method which is commonly used for the isotopic analysis of lead. A micro-scale appliance was devised to prepare tetramethyl lead from lead iodide in small quantities. Anisole was used as a solvent for the Grignard, s reaction with the intention of increasing partial pressure of tetramethyl lead in a gas mixture on which the isotopic analysis of lead was carried out. This led the authers to perform the isotopic analysis of lead in suchasmall quantity as 200 μg with a mass spectrometer, CEC21-103A. Detailed discussions are made on the whole experimental procedure as well as the analysis of mass spectra.