Adsorption and desorption of chlorogenic acid by macroporous adsorbent resins during extraction of Eucommia ulmoides leaves

Macroporous resin technology has unique advantages in the effective separation and purification of components from natural product. Evaluation of adsorption and desorption ability of chlorogenic acid on ten kinds of macroporous resins (AB-8, D4020, HPD-722, HPD-300, HPD-100, NKA, NKA-II, NKA-9, S-8, X-5) from Eucommia ulmoides Oliv. leaves extraction was carried in this study. Resin NKA-. exhibited the highest adsorption and desorption capacity and recovery. The adsorption parameters of NKA-. resin for chlorogenic acid can be accurately calculated with the Freundlich equation. The adsorption process was observed following a pseudosecond-order kinetic model. Dynamic testing was performed on a NKA-. resin-packed column where the breakthrough point was identified at four bed volumes of extract was loaded, and five bed volumes of 70% ethanol was required for complete desorption. After enrichment with macroporous adsorbent resin, the content of chlorogenic acid from extract increased 6.21-fold from 1.9% to 11.8%. The recovery of chlorogenic acid reached 87.9%.