Isotope ratio analysis comprises analyzing substance present in/as fluid solution, leading first and second part of solution over fluid chromatograph and producing and supplying the gas containing isotope marked substance for analysis

Isotope ratio analysis comprising analyzing a substance present in or as fluid solution, leading a first part of the solution over a fluid chromatograph and separating, producing gas from the eluate of the fluid chromatograph (in the presence of eluate) in a gas production unit, supplying the gas for analysis, producing gas from a second part of the solution in the gas production unit and supplying the gas for analysis, is new. Isotope ratio analysis comprising: (a) analyzing a substance present in or as fluid solution; (b) leading a first part of the solution over a fluid chromatograph and separating; (c) producing a gas (containing the isotope labeled analysis substance) from the eluate of the fluid chromatograph (in the presence of eluate) in a gas production unit; (d) supplying the produced gas for analysis; (e) producing a gas (containing the isotope labeled analysis substance) from a second part of the solution (without prior separation by the fluid chromatograph) in the gas production unit; and (f) supplying the produced gas for analysis. Independent claims are also included for: (1) determining isotope ratios of the carbon contained in a soluble analysis substance (preferably in a continuous fluid procedure) comprising: (a) producing gas from a solution containing the analysis substance, which contains the isotope information of carbon from inorganic and organic compounds in the analysis substance; and (b) supplying the produced gas for the isotope ratio analysis, at the same time a value is obtained for carbon altogether contained in the analysis substance from soluble compounds (totally dissolved carbon (TDC)); (2) determining the isotope ratios of the carbon contained in a soluble analysis substance (preferably in a continuous fluid procedure) comprising: (a) producing gas from the solution, which contains the isotope information of carbon only from organic compounds in the analysis substance; and (b) supplying the produced gas for the isotope ratio analysis, at the same time the value is obtained for the carbon altogether contained in the analysis substance from organic compounds (totally organic carbon (TOC)); and (3) a device for the isotope ratio analysis comprising a fluid chromatograph coupled with a unit (gas production unit) for the production of gas from the eluate of the fluid chromatograph, the gas production unit is coupled with a unit (gas separation unit) for the separation of the gas from the eluate in the remaining , the gas sepa