Investigation into the use of carbon isotope ratios (13C/12C) of Scotch whisky congeners to establish brand authenticity using gas chromatography-combustion-isotope ratio mass spectrometry

Volatile congeners of whisky have been analysed by gas chromatography-combustion-isotope ratio mass spectrometry (GC-C-IRMS). Acetaldehyde, ethyl acetate, n-propanol, isobutanol and amyl alcohol from a popular blended whisky have been separated using established GC conditions and their δ13C%. values determined. Eight samples of the whisky blend taken over the last 2 years of production have been analysed to allow the authentic range to be determined. A radar diagram has been used to graphically represent the δ13C%. data. This was used as a simple means of comparing the carbon isotope profiles of whiskies. Two other whisky samples were analysed and shown to differ from the whisky blend on the basis of the δ13C values.