Identification of organic substances by carbon-13 analysis - esp. for detecting chaptalisation of wine

摘要

Method of determining the origin of a hydrocarbonaceous substance (I) comprises subjecting (I) or a (I)-contg. prod., where (I) is in its original form or in a chemically converted form, to C-13 isotopic analysis. The analysis is pref. performed by burning a sample of the test substance to form CO2 and H2O, separating the prods., and subjecting the CO2 to mass spectrometric analysis to determine its C-13/C-12 ratio. The method is esp. useful for detecting "chaptalisation" of wine with cane sugar, since cane sugar (and alcohol formed from it) has a different C-13/C-12 ratio to grape sugar and beet sugar. Unlike chemical analyses, the method can be applied at any stage in the life of the wine (or prods. derived from it, e.g. brandy) and can be repeated if the results are contested. The detection limit for cane sugar alcohol in wine is ca. 0.5 g/100 ml.