ASSIGNMENT OF RAW-MATERIAL AND AUTHENTICATION OF SPIRITS BY GAS-CHROMATOGRAPHY, HYDROGEN-ISOTOPE AND CARBON-ISOTOPE RATIO MEASUREMENTS .1. ANALYTICAL METHODS AND RESULTS OF A STUDY OF COMMERCIAL PRODUCTS

Gas chromatography and the determination of natural isotope ratios are powerful analytical methods which can be used to check the authentici ty of alcoholic beverages and to detect any adulteration. To check the origin and the authenticity of commercial fruit spirits, whiskies, et c., 197 samples were analysed by gas chromatography, 2(H)-NMR and C-13 isotope mass spectrometry. The discrimination between different varie ties was demonstrated by bivariate and multivariate discriminant analy sis using different concentrations of volatile compounds such as metha nol, butan-1-ol, 2- and 3-methyl-butanol, benzaldehyde and hexanol as well as isotopic data like (D/H)(I), (D/H)(II) and C-13/C-12 isotopome rs of ethanol. The results show that by using multivariate discriminan t analysis it is possible to distinguish not only between different gr oups of spirits, e.g. those made of stone-fruit, malaceous fruit, grai n and corn, but also between individual varieties, such as cherry, plu m, mirabelle and apple, If the detection of highly rectified ethyl alc ohol of agricultural origin and the identification of its raw material s are required, then natural isotope ratios are the only discriminant analytical parameters available.