IUPAC

To design, compile and produce a new comprehensive Report on the Isotopic Compositions of the Elements, containing updated data and in a format suitable for the 21st Century.

In the past, CAWIA has produced several tables of the isotopic compositions of the elements (e.g. the most recent published in 1997) with isotopic data representing the best available measurements and representative materials. The aim of this project is to update and drastically upgrade this information, which has not been done in 7 years . Apart from the upgrading (incorporating new information obtained since 1997), the data handling procedures for the future table should also be modified to achieve recommended isotopic compositions that are fully in line with standard atomic weights. This is not always the case today.

With increasing importance of isotope ratio measurements in chemistry, environmental sciences, product authentication, forensic and life sciences, there is a need for an expanded and revised database on isotopic abundances in normal terrestrial materials and associated reference materials with standard atomic weights that reflect the current knowledge of isotopic compositions. This represents a major modification and an expansion of the present isotopic composition compilations. It will include a computer database accessible by the chemical community and will facilitate future updates, as new information becomes available.

Project phase 1: A special core task group consisting of R. Loss, J.K. Böhlke, K. Rosman, T. Coplen, T. Walczyk, M. Berglund, P. Taylor will hold a 3-day workshop August 5, 6, and 7 in Ottawa to develop guidelines for the new RICE data tables for use by the Subcommittee for Isotope Abundance Measurements (SIAM) when reviewing currently tabulated and subsequently reported isotopic compositions. On August 8 and 9 in Ottawa (IUPAC GA 2003), a forum of the full Task Group will meet to discuss the role of the new comprehensive "Report on the Isotopic Compositions of the Elements" for global user communities within the future structure of IUPAC, its Divisions, Subcommittees, and Commissions. A face-to-face meeting is critical, as it is the most cost effective way to engineer this novel system via in depth discussions with the relevant experts in a timely manner, which is important to this rapidly changing scientific subject. The Commission's collective experience over the past decades is that this is only viable approach, in view of the number of issues involved and the fact that experts from different scientific disciplines are needed. A new layout for the table of isotopic compositions will be drafted.

Project phase 2: By electronic communication, the core task group will further revise and then finalise these Guidelines and make a template for the novel table.

A novel calculation tool is available and will be distributed by IRMM for free to the project members. This software estimates the uncertainty of the isotope abundances from isotope ratios (and vice versa). It takes into account natural isotopic variation (e.g., from the IUPAC SNIF report), and it allows ratio conversion. It also allows the user to produce a standard atomic weight for the element. The intention is to have a hard link between the reservoir of raw literature data stored and the end products delivered. This will drastically improve archiving and it will allow for a more efficient review of previous decisions made by the Commission.