Determination of CO_2 origin (natural or industrial) in sparkling bottled waters by ~(13)C/ ~(12)C isotope ratio analysis

摘要

This paper describes an isotope control method designed to identify the origin of CO_2 in sparkling bottled waters. The method is based on the analysis of the ~(13)C/ ~(12)C ratio in the dissolved inorganic carbon (DIC) of carbonated bottled water. Natural carbonated natural water has δ ~(13)C_(PDB) (DIC) values between -8 per thousand and +7 per thousand. Generally, the industrial carbon dioxide injected into mineral bottled water is produced from hydrocarbons by burning or chemical processing. Hydrocarbons, and their derived CO_2, are characterised by a low ~(13)C/~(12)C ratio. Thus, a single analysis distinguishes the carbon dioxide in the bottled water (i.e. either from a natural source or added exogenous CO_2 of industrial origin). Rarely, CO_2 can be obtained from other industrial sources, mainly as a by-product of fermentation plants. Nevertheless, the carbon isotope fingerprint allows detection of the industrial gas injected in most of these cases.