Selective elution of tea catechins and caffeine from polyvinylpolypyrrolidone |
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Authors: | Fang‐Yuan Fan Quan Gan Zhan‐Bo Dong Kwan‐Jeong Song Xin‐Qiang Zheng Yue‐Rong Liang Jian‐Liang Lu |
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Affiliation: | 1. Zhejiang University Tea Research Institute, , Hangzhou, 310058 China;2. Wenzhou Vocational College of Science and Technology, , Wenzhou, 325006 China;3. Faculty of Bioscience and Industry, Jeju National University, , Jeju, 690756 Korea |
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Abstract: | Desorption of catechins and caffeine from polyvinylpolypyrrolidone (PVPP) was comprehensively investigated. The result showed that caffeine could easily be desorbed from PVPP by the tested solvents except n‐hexane, while catechins could only be thoroughly done by dimethyl sulphoxide (DMSO) and N, N‐dimethylformamide (DMF). Excellent desorption efficiency of DMSO and DMF might be attributed to their high dipole moments and H‐bond potentials. Addition of ethanol was recommended considering the elution efficiency and fluidity, but ethanol volume should be <40% (v/v) for DMSO or 20% (v/v) for DMF. Desorption would get to equilibrium within 1 h and followed the pseudo‐second‐order model. Caffeine and catechins could be separately desorbed through two‐stage elution procedure, that is, water or 20% aqueous ethanol for desorbing caffeine and part of nongalloylated catechins and DMSO/ethanol (8/2, v/v) for eluting the remaining catechins. Highly purified catechins (~95%) with high level (~70%) galloylated catechins would be achieved when the desorption procedure was applied in column chromatograph. |
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Keywords: | Caffeine desorption N N‐dimethylformamide dimethyl sulphoxide elution polyvinylpolypyrrolidone tea catechins |
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