An integrated continuous online platform for extraction, concentration and parallel preparative chromatography of phytochemicals: Application to green tea.

Conventional phytochemical preparation from botanical materials generally relies on discontinuous batch operations involving extraction, liquid-liquid partitioning, solvent concentration and preparative chromatography, resulting in limited process continuity and automation. In this study, an integrated continuous online platform was developed by coupling continuous ultrasound-assisted stirring extraction (CUASE), centrifugal phase separation (CE), a continuous concentration system (CCS), and parallel semi-preparative chromatography (PSPC). A dynamic emulsified extraction medium consisting of petroleum ether, ethanol and water (5:1:5, v/v/v) enabled simultaneous extraction and phase partitioning of hydrophilic and lipophilic phytochemicals, while the separated phases were continuously concentrated and directly transferred to parallel chromatographic systems for uninterrupted purification. The operating conditions of the CUASE and CCS were systematically optimized to ensure stable continuous operation. Using green tea as a representative botanical matrix, the integrated platform continuously isolated fifteen phytochemicals, including phenolic acids, catechins, purine alkaloids, chlorophylls and carotenoids, with purities exceeding 98.5%. A total of 11.42 g of purified products was obtained during a 3 h continuous operation. Compared with conventional batch-wise workflows, the proposed platform substantially improves process continuity, automation and preparative efficiency by integrating extraction, phase separation, concentration and preparative chromatography into a unified workflow. This work provides a practical engineering strategy for continuous and scalable preparation of phytochemicals from complex botanical matrices.