2H/1H ratio analysis of flavor compounds by on-line gas chromatography pyrolysis isotope ratio mass spectrometry (HRGC-P-IRMS):: citral

Based on H-2/H-1 measurements of commercial synthetic and natural citral (neral and geranial), online gas chromatography -pyrolysis-isotope ratio mass spectrometry (HRGC-P-IRMS) was used to determine the delta H-2(SMOW) values of citral in essential oils from Cymbopogon flexuosus and C. citratus, Litsea cubeba, Lippia citriodora, Melissa officinalis and the Citrus species C. aurantium, C. limon, C. sinensis, C. paradisi and C. aurantifolia. The technique allowed reliable differentiation of natural (delta H-2(SMOW) from -236 to -314 parts per thousand) from synthetic products (delta H-2(SMOW) from +38 to -197 parts per thousand), even when some samples can also have very negative delta H-2 values, e.g. -197 parts per thousand, but permitted no distinction within the origins from the various plant species. Copyright (C) 2001 John Wiley & Sons, Ltd.