IU13. IUPAC Commission on Atomic Weights and Isotopic Abundances (CAWIA)

Report to the 1999 IUPAP General Assembly

Titular and Associate members, National Representatives and Observers present at the Commission II.1 meeting of the 39th General Assembly of IUPAC were:

L. Schultz (Chairman, FRG), R. Vocke (Secretary, USA), M. Ebihara (Japan), R. Krouse (Canada), R. Loss (Australia), G. Ramendik (Russian Federation), P. Taylor (Belgium), J.K. Bohlke (USA), H. Dietze (FRG), T.P. Ding, (China), J. Gramlich (USA), J. de Laeter (Australia), P. De Bievre(Belgium), Y.K. Xiao (China), M. Shima (Japan), N. Greenwood (UK), S. Peiser (USA), E. Roth (France), T. Coplen (USA), K. Heumann (FRG), K. Rosman (Australia), D. Rokop (USA), M. Berglund (Sweden), S. Yoneda (Japan), H. Hidaka (Japan), R. Cohen (USA).

After the agenda was adopted, R. Krouse gave a brief obituary for Prof. H. Thode, a former commission member. L. Schultz followed this by briefing the members on the discussions at the division meeting. Considerable discussion followed this on ways to improve IUPAC visibility and specifically the visibility of Commission II.1. Possible solutions ranged from publishing the material generated for IUPAC in other journals to using the Web for innovative outreach. J. Moody, the chairman of Commission II.4, then made a short presentation concerning the mass spectrometric specific activities going on in his commission (II.4).

Next came the Review of the Atomic Weights 1997, based on the report from the Subcommittee for Isotopic Abundance Measurements (SIAM). For perhaps the first time in the Commission's history, the subcommittee, recommended no changes to the existing values for the atomic weights after reviewing all the published data. Only the range of possible atomic weights for Li was expanded in order to account for some extremely 6Li depleted reagents that are available commercially. These data will be reflected in the Table of Atomic Weights 1997, published biennially by the commission. A major effort was then directed towards completing another major summary document, the Isotopic Composition of the Elements 1997, which was last published over a decade ago. Data from the Subcommittee for Natural Isotopic Fractionation (SNIF) was critical for adjusting the isotope abundances of most of the 13 light elements whose atomic weights were affected by natural isotopic variations. This was the first time such data was available for harmonizing the table and was judged to have added significantly to the quality of the resulting publication. This document will be submitted to PAC before the end of 1997 also.

Following these actions, SNIF formally presented its report, Natural Isotopic Fractionation of Selected Elements which is slated for publication in PAC in the spring. As previously mentioned, this document clearly relates the effects of natural isotopic variations in 13 light elements on their atomic weight, principally in a graphical form. Discussions have confirmed the usefulness of this approach and SNIF was charged by the Commission with extending this type of survey to include gaseous elements and elements involved in radioactive decay.

The Commission then heard from the Subcommittee for Non-terrestrial Isotopic Abundance Data. They are nearing the completion of a monumental compilation and evaluation of data in the literature on isotopic anomalies in extra terrestrial materials. Such work was judged essential to the Commission if it is to properly interpret some terrestrial anomalies and their influence on atomic weights.

A working party then reported on how the Internet could impact the Commission. With over 3,600 hits to the keyword "Atomic Weight" and over 105 hits for "Periodic Table", this is truly a medium the Commission must further investigate for disseminating data on atomic weights and isotopic abundances. The Commission will set up a prototype site containing both publicly and commission-only accessible areas and will establish there a wide range of data types in order to evaluate its ease of use an potential impact.

The importance of the archives of the Atomic Weights Commission were also mentioned and ways to make it more accessible to members and historians of science was discussed.

Finally, attention was then directed towards future activities of the Commission. Principal among these was the formation of a working party that will begin an element by element review of the atomic weights. This was last done over a decade ago and in view of changes that have occurred to the atomic weights is now due for consideration. The working party expects to have a preliminary draft of this major review by 1999, at the next General Assembly.

R.C. Barber (Canada)

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