【摘要】 本文研究了活性炭、硅胶和氧化铝自水中吸附酪氨酸和苯丙氨酸。所得的结果表明,(1)在活性炭/水界面上两种氨基酸的吸附等温线均为Langmuir型。极限吸附量nsm、吸附常数b与介质pH值关系曲线大约在氨基酸等电点处有最大值,这可用介质pH对氨基酸溶解度的影响解释。在活性炭表面,氨基酸主要以两性离子平躺方式吸附。(2)在硅胶(氧化铝)/水界面上的吸附等温线为S形,吸附量仅为在活性炭/水界面上的1‰,在硅胶表面苯丙氨酸主要以电性作用吸附;在氧化铝表面酪氨酸以两性离子与表面形成氢键吸附。更多还原

【Abstract】 The adsorption of tyrosine and phenylalanine on active carbon, silica gel and alumina from aqueous solution has been studied. The results show that (1) The adsorption isotherms of tyrosine and phenylalanine from aqueous solution on active carbon are Langmuir抯 type. The limiting adsorbed amount smn and the adsorption constant b reach maximum near the isoelectric point (IEP) of amino acids. The result can be explanied by changed solubilities of amino acids at different pH values. The solubilities of amino acids reach minimum at IEP. Tyrosine and phenylalanine are adsorbed mainly in the form of zwitterions and adsorbed with their molecules parallel to the surface. (2) The adsorption isotherms of tyrosine and phenylalanine at the silica gel (alumna)/water interfaces are S type, and the adsorbed amounts are 10-3 times lower than on the active carbon/water interface. The phenylalanine at silica gel/water interface is adsorbed through electrostatic attraction, and at alumina/water interface the tyrosine is adsorbed in the form of zwitterion.更多还原