Precise and accurate δ13C analysis of rock samples using Flash Combustion–Cavity Ring Down Laser Spectroscopy

摘要: The ratio of 13C to 12C in marine sedimentary rocks holds important clues the evolution carbon cycle through Earth history. Isotopic analyses are traditionally carried out using isotope mass spectrometry (IRMS), but this technique is labor-intensive, expensive and requires expert know-how. Here, we measure 13C/12C natural samples Combustion Module–Cavity Ring Down Spectroscopy (CM-CRDS) with an average precision a standard reproducibility 0.05‰ 0.2‰ (1 sd, n = 17), respectively. accuracy was determined from certified reference compounds be <0.3‰. This comparable performance routine laboratory <0.11‰ (1σ). We report data Cambrian succession organic-rich shales straddling positive δ13Corg excursion 2‰. conclude that optical determination bulk organic δ13C provides high alternative applicable for geochemical analyses.