NOTICE: Due to a lapse in annual appropriations, most of this website is not being updated. Learn more.

Form submissions will still be accepted but will not receive responses at this time. Sections of this site for programs using non-appropriated funds (such as NVLAP) or those that are excepted from the shutdown (such as CHIPS and NVD) will continue to be updated.

U.S. flag

An official website of the United States government

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

PUBLICATIONS

New Guidelines for d13C Measurements

Published

Author(s)

T Coplen, W A. Brandt, M Gehre, Manfred Groning, HAJ Meijer, Blaza Toman, Jennifer R. Verkouteren

Abstract

Consistency of 13C measurements can be improved 39-47% by anchoring the 13C scale with two isotopic referencematerials differing substantially in 13C/12C. It isrecommended that 13C values of both organic andinorganic materials be measured and expressed relativeto VPDB (Vienna Peedee belemnite) on a scale normalizedby assigning consensus values of -46.6 to L-SVEClithium carbonate and +1.95 to NBS 19 calciumcarbonate. Uncertainties of other reference material valueson this scale are improved by factors up to two ormore, and the values of some have been notably shifted:the 13C of NBS 22 oil is -30.03 .
Citation
Analytical Chemistry
Volume
78 No 7
Pub Type
Journals

Citation

Coplen, T. , Brandt, W. , Gehre, M. , Groning, M. , Meijer, H. , Toman, B. and Verkouteren, J. (2006), New Guidelines for d13C Measurements, Analytical Chemistry (Accessed October 11, 2025)

Issues

If you have any questions about this publication or are having problems accessing it, please contact [email protected].

Created March 31, 2006, Updated October 12, 2021
Was this page helpful?