Determination of δ ~(13)C Volues of Wine Ethanol by Isotope Ratio Mass Spectrometry
An elementary analysis-isotope ratio mass spectrometric( EA-IRMS) method was developed for the determination of δ 13C of ethanol in wine. Three distillation apparatuses,including rotary evaporator,all-glass distillation device and fully automatic distillation control system,were compared for wine ethanol distillation. The analytical conditions for EA-IRMS were optimized. The repeatibility and reproducibility were satisfactory with relative standard deviations less than 0.25‰. The δ 13C values of ethanol in two wine samples from FIT- PTS were determined and the accuracy was better than 0.2‰. 40 wine samples from 16 countries and regions were determined by both liquid chromatography-isotope ratio mass spectrometry( LC-IRMS) and this method, and the δ 13C values of ethanol of these samples were between -23. 90‰ and-28. 29‰. Δδ( EA-LC) max of the results was less than 0.3‰,and a strong correlation( R2= 0.9749) was found between the two methods. The isotope fractionation effect was not found in this method,which was suitable for the determination of δ 13C of ethanol in wine.