The removal of lead from ginseng ethanol extracts by a fixed-bed column filled with an adsorbent bearing amine and carboxyl groups was investigated. The Pb2+ content was determined by inductively coupled plasma mass s...The removal of lead from ginseng ethanol extracts by a fixed-bed column filled with an adsorbent bearing amine and carboxyl groups was investigated. The Pb2+ content was determined by inductively coupled plasma mass spectrometry. When the flowrate increased from 0.12 to 0.34 ml·min-1 , the column exhibited a marked increase in percentage of lead removal from 54.9% to 92.3%. Further increase in the flowrate did not bring evident changes to the lead removal, whereas an increase in the temperature could reinforce adsorption further, suggesting that the adsorption process was controlled by external film diffusion below the flowrate of 0.34 ml·min-1 , and by the intraparticle pore diffusion of lead ions when the flowrate exceeded it. A low remaining lead amount in extracts such as 0.11 mg·kg-1 (extracts powder) was achieved. The adsorbents also adsorbed effective constituents to some extent. But 88% of constituents adsorbed were taken off using a 70% ethanol aqueous solution.展开更多
基金Supported by the National＇Natural Science Foundation of China （20976012, 20806009）, and the Specialized Research Fund for the Doctoral Program of Higher Education （20070007055, 20091101110035）.
文摘The removal of lead from ginseng ethanol extracts by a fixed-bed column filled with an adsorbent bearing amine and carboxyl groups was investigated. The Pb2+ content was determined by inductively coupled plasma mass spectrometry. When the flowrate increased from 0.12 to 0.34 ml·min-1 , the column exhibited a marked increase in percentage of lead removal from 54.9% to 92.3%. Further increase in the flowrate did not bring evident changes to the lead removal, whereas an increase in the temperature could reinforce adsorption further, suggesting that the adsorption process was controlled by external film diffusion below the flowrate of 0.34 ml·min-1 , and by the intraparticle pore diffusion of lead ions when the flowrate exceeded it. A low remaining lead amount in extracts such as 0.11 mg·kg-1 (extracts powder) was achieved. The adsorbents also adsorbed effective constituents to some extent. But 88% of constituents adsorbed were taken off using a 70% ethanol aqueous solution.
