An official website of the United States government
Here’s how you know
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.
Coplen, T.
, Brand, W.
, Gehre, M.
, Groning, M.
, Meijer, H.
, Toman, B.
and Verkouteren, R.
(2006),
New Guidelines for delta-13-C Measurements, Analytical Chemistry
(Accessed April 20, 2024)