The report describes the advances in instrumentation and the research activities of the Analytical Mass Spectrometry Section during the period July 1968 to June 1969.Chemical and mass spectrometric procedures are described for the determinations of the absolute isotopic abundance ratios of natural rubidium, boron in a natural boric acid and a 10B enriched boric acid, and of uranium in six SRMs.Procedures are also described for the determination of trace amounts of copper and lead in steel, and silver, copper, boron and uranium in glass by isotope dilution mass spectrometry.(Author).

The report describes the advances in instrumentation and the research activities of the Smslytical Mass Spectrometry Section during the period July 1969 to June 1970.Advances in instrumentation include the construction of a computer controlled mass spectrometer with appropriate interconnecting components, power supplies with greatly increased stability and the utilization of a magnetic field control.Elements studied during this period include: B, Cu, Ag, Pb, T1, U, Pu, K, Rb, Ni and Mo.Mass spectrometric procedures are given for Pb, T1, U, K, Ni and Mo.Chemical procedures for the intercomparison of redox standards are also given.(Author).