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Abstract
pH‐Zone‐refining countercurrent chromatography was applied to the separation of alkaloids from a crude extract of green tea using a multilayer coil planet centrifuge. After methyl tert‐butyl ether and water were equilibrated, triethylamine (10 mM) was added to the organic phase as a retainer and hydrochloric acid (10 mM) was added to the aqueous phase as an eluter. The separation was performed by eluting the aqueous phase while the organic phase was used as the stationary phase. From 3 g of the extract, 2.2 g caffeine and 0.07 g theophylline were separated within about 4 h.
Acknowledgment
The work is supported by the National Natural Science Foundation, TRAPOYT, and the Yunnan Province's Natural Science Foundation of China.