Deuterium/Hydrogen Measurements in Wines and Fruit Juices by Platinum Catalysed Equilibration Method

Abstract Isotopic analysis is currently applied for detecting watering and illegal addition of exogenous sugars in wines, fruit juices and other foodstuffs. In the particular case of detection of watering, the determination of oxygen and deuterium isotope ratios is suitable. Until now, deuterium measurement has rarely been carried out routinely because of technical difficulties. The two usual methods are based on reduction of water with zinc or uranium. However, they present some inconvenience, originating mainly from the handling of the catalyst and/or the preparation of the samples, which restricts their application to specialized laboratories. We have investigated the applicability and the potential offered by a new method based on equilibration of the samples with hydrogen gas using a platinum catalyst, and present first results obtained on wines and fruit juices. Moreover, the possibility of successively measuring hydrogen and oxygen isotope ratios on the same aliquot makes the system very attractive for routine analysis.