Stable oxygen isotope content of water of EU data-bank wines from Italy, France and Germany

The application of oxygen isotope analysis to wine water (according to EU r egulation no. 822/97) to determine a wine's origin, and check that it has n ot been adulterated is gaining increasing importance in both laboratories a nd industry. Using samples of Italian, French and German wines from the EU wine data bank (EU-DB), good agreement between the results from participati ng laboratories was demonstrated. Close correlations between the oxygen iso tope contents of must and related wine water were found for samples from al l countries. Based on the results of the delta(18)O values for EU-DB wines from 1991 to 1996 from Italy, France and Germany, we describe and discuss t he main factors which are responsible for the variation of the oxygen isoto pe ratios of wine water. The examination of spiked samples demonstrated the usefulness of delta(18)O analysis for the detection of the watering down o f wine. The possibility of origin assignment, preferably if the determinati on of the delta(18)O value by isotope ratio mass spectrometry (IRMS) is emp loyed together with the determination of the site-specific hydrogen isotope content of wine ethanol by H-2-NMR and the measurement of delta(13)C value s of ethanol by IRMS, is outlined.