用酰胺型键合固定相测定茶叶中嘌呤碱含量

Detection of Three Purines in Tea Using Amide-type Stationary Phase for High Performance Liquid Chromatography

采用自制包埋极性官能团———酰胺键的键合固定相(AOBP),在甲醇/水(V/V=20/80)二元流动相条件下,对系列不同产地茶叶中的嘌呤碱进行了快速有效的分离测定。结果表明,由于AOBP固定相中残留硅羟基活性得到很好抑制,可在不加酸碱调节剂条件下对可可碱、茶碱和咖啡碱进行良好分离,检出限分别为0.21、0.042和0.18mg/L;线性范围分别可达到1.67～500L、0.3～167和1.67～833mg/L,同时还探讨了分离机理。

A new amide-type bonded phase(AOBP) column made in our laboratory was. firstly used to, separate three purines in series of tea. The interactions between basic analytes and silanol on the packing were restrained effectively because of the existence of polar group-amide, so the three basic compounds can be separated simply and effectively under methanol and water (V/V = 20/80) as binary mobile phase. The results show the linear ranges of theobromine, theophylline and caffeine can reach to 1.67 similar to 500 mg/L, 0.3 similar to 167 mg/L, 1.67 similar to 833 mg/L, and the limits of detection at three times of noise are 0.21 mg/L, 0.042 mg/L, 0.18 mg/L, respectively. The separation mechanism of basic compounds on the AOBP was also discussed.