Gesa Kutschera, Lots of references are available here are some of them: Atekwana, E.A., Krishnamurthy, R.V., 1998. Seasonal variations of dissolved inorganic carbon and d13C of surface waters: applications of a modified gas evolution technique. Journal of Hydrology 205, 265-278. Amiotte-Suchet, P., Aubert, D., Probst, J.L., Gauthier-Lafaye, F., Probst, A., Andreux, F., Viville, D., 1999. d13C pattern of dissolved inorganic carbon in a small granitic catchment: the Strenbach case study (Vosges mountains, France ). Chemical Geology 159, 129-145. Aucour, A.-M., Sheppard, S.M.F., Guyomar, O., Wattelet, J., 1999. Use of 13C to trace origin and cycling of inorganic carbon in the Rhône river system. Chemical Geology 159, 87-105. Yang, C., Telmer, K., Viezer, J., 1996. Chemical dynamics of the St-Lawrence riverine system: DH2O, 18OH2O, 13CDIC, 34Ssulfate, and dissolved 87Sr/86Sr. Geochimica et Cosmochimica Acta 60; 5, 851-866. I also have a lab protocol if you want to know the technique we use. E-mail me at the address below if want it ([log in to unmask]). At 10:45 00-06-21 +0800, you wrote: >Did anybody measure delta 13 C of dissolved inorganic carbon or knows a >reference where methods are described and/or results are presented? Jean-François Hélie ---------------------------------------------------- GEOTOP-UQAM Université du Québec à Montréal C.P.8888 succ. Centre-ville H3C 3P8 Tél: (514) 987-3000 #4631 Fax: (514) 987-3635 e-mail: [log in to unmask] Bureau: PK-7515