天然咖啡因与人工合成咖啡因的鉴别

Identification of Natural and Synthetic Caffeine Caffeine

[目的]通过研究咖啡因自身结构差异性,得到一种新的鉴别天然与人工合成咖啡因的方法。[方法]通过茶叶提取天然高纯度咖啡因,利用连续流同位素质谱法检测被测咖啡因样品元素的同位素比值,根据其差值来进行判定,鉴别出天然咖啡因与合成咖啡因。[结果]研究表明,利用连续流同位素质谱法,将实验室提取制备的天然牛磺酸与市场购买的人工合成牛磺酸进行元素的同位素比值测定,发现天然咖啡因的δ13C同位素比值为-25,δ15N同位素比值为-1.5;而人工合成咖啡因的δ13C同位素比值为-36,δ15N同位素比值为-10,其同位素比值存在明显的差异,根据同位素比值的差异性可以对天然与人工合成的咖啡因进行鉴别判定。[结论]天然咖啡因和合成咖啡因的δ13C、δ15N同位素比值存在明显的差异,可通过其差异性比值鉴别出天然与人工合成咖啡因。

[Objective] Through study on caffeine itself structure difference,a new method for identifying natural and synthetic caffeine was obtained. [Method] The natural high purity caffeine was extracted from tea,continuous flow isotope mass spectrometry was used to detect the ratio of isotope,according to the difference to identify natural and synthetic caffeine. [Result] The ratio of isotope was determined on natural taurine and artificial synthesis taurine. It was found that the ratio of isotope ^δ13C is-25,^δ15N is-1. 5 in natural caffeine; ^δ13C is-36,^δ15N is-10 in synthetic caffeine. According to the significant sifference of the ratio of isotype,natural and synthetic caffeine can de distinguished. [Conclusion] The ratio of isotope（^δ13C,^δ15N） in natural and synthetic caffeine has significant differences,which can be used as the way for identification.