固态法白酒与固液法白酒的同位素鉴别技术

固态法白酒和固液法白酒的鉴别是当前白酒行业所面临的技术难题。本实验以碳稳定同位素为指标，建立了气相色谱-燃烧-同位素质谱(GC-C-IRMS)联用方法测定白酒中乙醛、乙醇、丙醇、异丁醇、异戊醇、乳酸乙酯等主要挥发性物质中的δ¹³C。测定了43个传统固态法白酒样品，其乙醇δ¹³C分布范围为（-17.65±1.31）‰，测定了24个流通领域白酒样品，其乙醇δ¹³C分布范围为（-15.30±1.41）‰，经t检验分析，二者存在显著性差异(P<0.01)；t检验结果还表明，传统固态法白酒样品和流通领域白酒样品中异戊醇和乳酸乙酯中δ¹³C也存在显著差异。模拟实验发现，白酒中乙醇δ¹³C与添加玉米酒精含量呈正相关关系；添加的玉米酒精和挥发性香气物质会改变白酒中的乙醇及微量组分的稳定碳同位素比值，因此稳定同位素技术将有望成为固态法白酒和固液法白酒的有效鉴别手段。

Application of Stable Isotope Technique on Distinguish Between Chinese Spirit by Traditional Fermentation and Chinese Spirit Made from Traditional and Liquid Fermentation

It is a technical problem in Chinese spirit industry to distinguish between Chinese spirit by traditional fermentation and Chinese spirit made from traditional and liquid fermentation. Methods for the determination ofδ¹³C values of major volatile substances (such as acetaldehyde, ethanol, isobutanol, isoamyl alcohol, ethyl lactate, etc) in Chinese spirit by gas chromatography combustion coupled to isotopic ratio mass spectrometry （GC-C-IRMS) were developed. The averageδ¹³C value of ethanol in Chinese spirit made by traditional fermentation is （-17.65±1.31）‰，and the value of what is called traditional Chinese spirit in market is （-15.30±1.41）‰, so t-test result is significant difference(P<0.01). The simulation test show that the carbon isotope ratio of ethanol observed in Chinese spirit are positive relative to those of the corresponding maize ethanol; it is significant differences onδ¹³C of isoamyl alcohol and ethyl lactate between reference samples and commercial samples. The results show that theδ¹³C value of ethanol and volatile aroma components in Chinese spirit (made from traditional and liquid fermentation) will be changed when added maize ethanol and exogenous volatile aroma components, so stable isotope technique will be used in distinguish between Chinese spirit made by tracitional fermentation and Chinese spirit made from traditional and liquid fermentation.