Acta Chimica Sinica ›› 2019, Vol. 77 ›› Issue (11): 1203-1210.DOI: 10.6023/A19080316 Previous Articles    



郭文娟*(), 于洁, 代昭, 侯伟钊   

  1. 天津工业大学 化学与化学工程学院 天津 300387
  • 投稿日期:2019-08-29 发布日期:2019-10-21
  • 通讯作者: 郭文娟
  • 基金资助:

A New Method for Enriching baicalin in Scutellaria baicalensis Georgi by Metal Organic Framework Material ZIF-8

Guo Wenjuan*(), Yu Jie, Dai Zhao, Hou Weizhao   

  1. Tianjin Polytechnic University, School of Chemistry and Chemical Engineering, Tianjin 300387
  • Received:2019-08-29 Published:2019-10-21
  • Contact: Guo Wenjuan

This work aims to explore a new method for the efficient enrichment of baicalin in Scutellaria baicalensis Georgi by using metal organic frameworks (MOFs) materials, and to open up new applications for MOFs in the adsorption direction. The zeolitic imidazolate framework-8 (ZIF-8) was synthesized by solvothermal method and characterized by structure to ensure its accurate synthesis. Baicalin was extracted from Scutellaria baicalinsis Georgi by ethanol extraction and acid precipitation method. The ZIF-8 was used to carry out the static adsorption experiment on the crude extract of Radix Scutellariae. After the adsorption equilibrium was reached, the mixture was centrifuged, and the residual concentration of baicalin was detected by high performance liquid chromatography method (HPLC). The recovered saturated adsorbed ZIF-8 material was washed with water and dried, and the phosphate buffered saline (PBS) solution of pH 6.8 was used as a desorption solution, and the desorption was performed by shaking. The content of baicalin in the desorbed solution was determined by HPLC to calculate the desorption rate and achieve the purpose of adsorbent recovery. In the adsorbing process, the effects of adsorbent dosage, pH and adsorbate concentration of the crude extract of Radix Scutellariae were also optimized, and the response surface test (RSM) was performed using Design Expert software to obtain optimal adsorption conditions. Under these conditions, the adsorption rate of ZIF-8 to baicalin in Radix Scutellariae was as high as 98.22%, and the adsorption effect was not significant on other components in Radix Scutellariae. The desorption rate of ZIF-8 adsorbed baicalin in pH 6.8 solution was 62.46%, and the purity of baicalin increased from 21.55% before adsorption to 64.27% after desorption, and ZIF-8 had good stability before and after adsorption, and the recovery rate reached 83.50%. Therefore, ZIF-8 has potential application value in the adsorption and purification of baicalin. The adsorption law and mechanism of ZIF-8 on baicalin were studied:The adsorption of baicalin on ZIF-8 accorded with the quasi-second-order kinetic equation, and the equilibrium adsorption data accorded with the Langmuir adsorption isotherm model.

Key words: metal-organic framework, adsorption, X-ray photoelectron spectroscopy