Carbon

carbon stable isotope lab

Stable Isotopes - Carbon - 13C/12C

Abundance
12C= 98.89 % atom
13C= 1.11 % atom
14C= 10-4 % atom (radioactive, analysed at the GNS Rafter Radiocarbon Lab)

Gas analysed
CO2

Recommended Scale
VPDB (Vienna Pee Dee Belemnite, absolute isotope ratio (11237 ± 60) x 10-6 [Craig, 1957])

Equipment
Europa Geo 20-20 dual inlet for CO2 gas samples
Europa Geo 20-20 continuous flow coupled with an EA for solid organic samples
Europa Geo 20-20 continuous flow coupled with CSIA-GC for various gas and liquid samples
GVI Isoprime dual inlet for carbonate samples
GVI Isoprime coupled to Eurovector EA

    Precision‰ Preferred sample size Minimum sample size Price
SOLIDS
13C & 18O carbonates 0.3 & 0.1 2mg as CaCO3 0.5mg  
13C & 15N organic material 0.1 & 0.3 800μg C 100μg N 100μg C
20μg N
 
13C organic material 0.2 800μg C 100μg C  
LIQUIDS
13C bicarbonates 0.2 1.0mg HCO3 0.2mg HCO3  
GAS
13C & 18O CO2 0.1 2ml STP* 0.2ml STP*  
13C methane 1 2ml STP* 0.2ml STP*  
13C & D methane 1 & 3 5ml STP* 1ml STP*  
13C CO2 in alkali 0.2 20mg as BaCO3 2mg as BaCO3  
*Standard Temperature and Pressure
**Depending on TOC