Phenylalanine and Arginine Adsorption in Zeolites X, Y, and β

Abstract

This paper documents a continuation of work published in Langmuir 2005, 21, 8743-8750. We report new aspects of this amino acid adsorption study, including the effect of changing zeolite framework type and results from adsorption of mixed amino acids. In single-amino-acid adsorption experiments, zeolite Y (Si/Al=2.5) was found to adsorb no phenylalanine while admitting arginine to a similar extent as observed with zeolite beta. Using this zeolite Y, we measured mixed-amino-acid separation selectivities for arginine/phenylalanine as large as 25,000 or 2 orders of magnitude larger than the corresponding selectivities measured with zeolite beta.

Adsorption and Polymerization of Amino Acids on Mineral Surfaces: A Review

“…Titus et al (2003) reported that the zeolite ZSM5 has a very high selectivity for Phe and Tyr over Ala and Trp, the latter compounds being adsorbed in undetectably low amounts. No explanation was offered; the exclusion of Trp could be due to steric factors, but not that of Ala. On zeolites X, Y and β, Arg adsorption was strongly favored in (Phe+Arg) mixtures (Krohn and Tsapatsis 2006) at high pH, which is probably related with the acid-basic speciation of Arg.…”

“…If a covalent bond is formed ("Specific Adsorption by Covalent Bond Formation"), no influence of I is expected (Hayes et al 1988;Giacomelli et al 1995). More complicated adsorption mechanisms may also be revealed by their dependence on I (Krohn and Tsapatsis 2006).…”

“…On materials such as clays or zeolites, this refers to the substitution of one charge-compensating ion by another, e.g. K + by Na + , or Na + by H 2 Arg + (Krohn and Tsapatsis 2006): both before and after exchange, the ion is held by electrostatic adsorption. However, on amphoteric oxides, the same term is used to characterize an adsorption mechanism where an ion causes the deprotonation of a surface S-OH group (e.g.…”

ATR-IR spectroscopic study of L-lysine adsorption on amorphous silica

“…Interactions between mineral surfaces and amino acids have attracted much interest in a wide range of fields such as aqueous geochemistry [1], soil science [2], technologies for the separation and purification of amino acids [3,4], and the origins of life [5,6]. For example, dissolved amino acids influence the rate of silica dissolution [7], the rate of hydroxyapatite growth [8], and the morphology of hematite precipitates [9].…”

“…1 shows the changes in the dissociation states of lysine as a function of pH [15]). Therefore, amino acids show various adsorption behaviors including electrostatic attraction, covalent bonding, hydrogen bonding, and hydrophobic interactions [3,4,6,16]. This variety of adsorption behaviors often makes data interpretation difficult, and in some cases inconsistent conclusions have * Corresponding author.…”