New guidelines for delta13C measurements.
Consistency of delta13C measurements can be improved 39-47% by anchoring the delta13C scale with two isotopic reference materials differing substantially in 13C/12C. It is recommended that delta13C values of both organic and inorganic materials be measured and expressed relative to VPDB (Vienna Peedee belemnite) on a scale normalized by assigning consensus values of -46.6 per thousand to L-SVEC lithium carbonate and +1.95 per thousand to NBS 19 calcium carbonate. Uncertainties of other reference material values on this scale are improved by factors up to two or more, and the values of some have been notably shifted: the delta13C of NBS 22 oil is -30.03 per thousand.
Coplen
Tyler B
TB
U.S. Geological Survey, 431 National Center, Reston, Virginia 20192, USA. tbcoplen@usgs.gov
Brand
Willi A
WA
Gehre
Matthias
M
Gröning
Manfred
M
Meijer
Harro A J
HA
Toman
Blaza
B
Verkouteren
R Michael
RM
D002119:Calcium Carbonate / Q000032:analysis*; D002244:Carbon / Q000032:analysis*; D002247:Carbon Isotopes / Q000032:analysis*; D017408:Guidelines as Topic; D016651:Lithium Carbonate / Q000032:analysis*; D013058:Mass Spectrometry; D012015:Reference Standards
D002247:Carbon Isotopes; D016651:Lithium Carbonate; D002244:Carbon; D002119:Calcium Carbonate