USGS44, a new high-purity calcium carbonate reference material for δ¹³ C measurements.

ABSTRACT:

Rationale

The stable carbon isotopic (δ¹³ C) reference material (RM) LSVEC Li₂ CO₃ has been found to be unsuitable for δ¹³ C standardization work because its δ¹³ C value increases with exposure to atmospheric CO₂ . A new CaCO₃ RM, USGS44, has been prepared to alleviate this situation.

Methods

USGS44 was prepared from 8 kg of Merck high-purity CaCO₃ . Two sets of δ¹³ C values of USGS44 were determined. The first set of values was determined by online combustion, continuous-flow (CF) isotope-ratio mass spectrometry (IRMS) of NBS 19 CaCO₃ (δ¹³ C_VPDB  = +1.95 milliurey (mUr) exactly, where mUr = 0.001 = 1‰), and LSVEC Li₂ CO₃ (

SUBMITTER: Qi H 

PROVIDER: S-EPMC7816275 | biostudies-literature | 2021 Feb

REPOSITORIES: biostudies-literature