Adsorption behavior of L-tryptophan on ion exchange resin

Abstract

A batch method was applied to investigate the adsorption behavior and mechanisms of L-tryptophan (Ltrp) on ion exchange resins. HZ-001 and JK006 were proved to be ideal adsorbents due to their large loading capacity and favorable selective adsorption for L-trp. Langmuir, Freundlich, and Dubinin-Radushkevich equations were applied to simulate the experimental data to describe the adsorption process of L-trp onto HZ-001 and JK006. The maximum loading capacity (at pH 5.0, 30 o C), determined by the Langmuir and Dubinin-Radushkevich models, was close to each other (833 mg/g vs. 874 mg/g) for HZ-001, while discrepant (833 mg/g vs. 935 mg/g) for JK006. Three diffusion-controlled kinetic models were utilized to analyze the results in order to identify the adsorption mechanism. The adsorption kinetics of L-trp onto cation exchange resins was investigated under different experimental conditions, including initial solution pH, temperature, initial L-trp concentration, and adsorbent dosage. Moreover, the diffusion process of L-trp onto HZ-001 and JK006 was evaluated at different initial adsorbate concentrations. The thermodynamic parameters, obtained from the kinetic data, demonstrated that L-trp could be adsorbed spontaneously onto both resins.

Adsorption and Separation of Aromatic Amino Acids from Aqueous Solutions Using Metal–Organic Frameworks

“…Thus, the adsorption of amino acids on solid porous materials is a worthwhile alternative. For instance, ion-exchange resins are able to separate amino acids based on their pH-dependent charge in water. − When aromatic ion-exchange resins are used, pH modification of the aqueous medium can facilitate uptake by adding electrostatic interactions to the strong dispersive forces (π–π): the pH is modified so that either pH > p K a of −NH 3 + (≈9.2) for anion-exchangers or so that pH < p K a of −COOH (≈2.2) for cation-exchangers. These materials are also known to swell considerably in water, which involves a large volume expansion of the resin by intercalation of water molecules between the resin’s polymer chains.…”

Optimization of Process Parameters forε-Polylysine Production by Response Surface Methods

“…In contrast, the adsorbate needs to diffuse into the intraparticle of the resins before being absorbed by the sites in the intraresin [28]. The diffusion to the intraparticle is a slow adsorption process subjected to fast adsorption stage, slow adsorption stage, and equilibrium stage [29][30][31]. As shown in Figure 1(d) for the -PL adsorption efficiency-time curves of the resins (Figure 1(d)), the -PL adsorption on all five resins was subjected to three stages with the extension of adsorption time as described above.…”

Study on the adsorption kinetics of L-citrulline from the pseudo aqueous solution of watermelon rind on ion exchange resin

“…Ion exchange chromatography has been utilized widely in the industrial separation and purification of amino acids due to their amphoteric behavior. These low cost and reusable adsorbed resins show selective adsorption capacity based on their differential charges and chemical stability [14]. Luo et al (2010) investigated the adsorption behavior and mechanisms of L-tryptophan (L-trp) on HZ-001 and JK006 resins [14].…”

“…These low cost and reusable adsorbed resins show selective adsorption capacity based on their differential charges and chemical stability [14]. Luo et al (2010) investigated the adsorption behavior and mechanisms of L-tryptophan (L-trp) on HZ-001 and JK006 resins [14]. Kim et al (1995) also investigated the intraparticle transport of amino acids, phenylalanine and tyrosine through a macroreticular cation exchange resin, Amberlite 200, with a finite batch adsorber [15].…”