Subcommittee on Isotope Abundance Measurements (SIAM)
Chairman: Prof Ronny Schönberg
Secretary: Dr Manfred Gröning
2011-027-1-200 - Evaluated Published Isotope Ratio Data (2011-2013)
The Subcommittee on Isotope Abundance Measurements is a subcommittee of CIAAW. It consists of a group of experts in isotope mass spectrometry, statisticians, and measurement scientists who are concerned with the measurement of isotopic abundances and variations of those abundances in natural materials. As such, it furnishes the technical expertise to the Commission, the Inorganic Division, and IUPAC on the isotopic abundances of the elements and the atomic weights of the elements as determined from those abundances.
The responsibilities of SIAM are:
• To evaluate all published data on measurements of the isotopic abundances of all the elements.
• To examine the literature on measurements of the isotopic abundances of all the elements.
• To critically evaluate these data.
• To prepare a Table of “Isotopic Compositions of the Elements” for the use of the Commission in recommending new values of Atomic Weights of the Elements. This Table will be published for general use at the discretion of the Commission.
• To prepare a data base of isotopic abundances and variations in such a form as to be computer readable in reasonable format. This will be made available to IUPAC and to others as directed by the Commission.
• To provide technical expertise to the Commission, the Division, and IUPAC on matters pertaining to the atomic weights of the elements, isotopic abundances, and possible variations of these, and on measurement methods and statistical procedures.
Although SIAM has concerned itself primarily with isotope mass spectrometry in all of its forms because it has been the dominant measurement procedure in the past years, it recognizes that other methods, such as precision X-ray measurements and laser methods, may contribute to these data, and SIAM must be aware of efforts in these areas.