CO2 conversion by H3PO4, extracted CO2 introduced into continous flow IRMS for 13C/12C analysisThis method follows the general principles described in Assayag et al. (2006), which emphasizes the importance of maintaining the same water : H3PO4 volume ratio for standard solutions and samples (ratio of 10 in this case) in order to obviate issues regarding isotopic fractionation between CO2 (g) and CO2 (aq).References Assayag, N., Rivé, K., Ader, M., Jézéquel, D., and Agrinier, P. (2006). Improved method for isotopic and quantitative analysis of dissolved inorganic carbon in natural water samples. Rapid Communications in Mass Spectrometry 20, 2243–2251