Project Details Technical Guidelines for Isotope Abundances and Atomic Weight Measurements

Project No.: 
Start Date: 
01 May 2010
End Date: 
01 September 2013


To prepare guidelines for isotope abundance and atomic weight measurements in a form suitable for publication. This document is directed at the mass spectrometric community.


Recent experience has indicated that there is a lack of understanding in mass spectrometric protocols and uncertainty determinations. The intention of this project is to improve the quality of the reporting isotopic measurements in the international literature.

We anticipate a publication in International Journal of Mass Spectrometry


July 2010 – project announcement published in Chem. Int. Jul-Aug, p. 22

Update Sep 2012: The Commission on Isotopic Abundances and Atomic Weights (CIAAW) met in Calgary (2012): The question as to what constitutes a fully calibrated isotope amount ratio measurement still remains a topic of active research and debate. For years, the definitive calibration approach has been by means of synthetic mixtures of highly enriched isotopes with known chemical purity to give gravimetrically defined ratios.

Paper published by Juris Meija: “Calibration of isotope amount ratios by analysis of isotope mixtures” Anal. Bioanal. Chem. 2012, 403, 2071-2076.

An updated edition of the CIAAW’s Technical Booklet, currently in its 5th edition (1999), will be produced by the next Commission meeting (2013).

May 2013 – Atomic weights of the elements 2011 (IUPAC Technical Report) published in Pure Appl. Chem., 2013, Vol. 85, No. 5, pp. 1047-1078;

project completed
last updated 6 Sep 2013