Liquid-phase adsorptions ionic strength

For instance, in liquid-phase adsorption, it has been established that the adsorption capacity of an activated carbon depends on the adsorbent s pore structure, ash content, functional groups [184-186], the nature of the adsorbate, its p//a, functional groups present, polarity, molecular weight, and size [187], and, finally, the solution conditions, such as pH, ionic strength, and the adsorbate concentration [188],... 

Ideally, the column matrix should be inert with regard to the molecules to be separated. If electrostatic or hydrophobic interactions occur between proteins and the stationary phase, it is recommended, respectively, to increase or decrease the ionic strength of the liquid phase, otherwise partial adsorption of the protein may cause a delay in elution from the column. This would cause a longer elution time than that expected based on the molar mass. 

In a series of studies we recently demonstrated (29, 30, 63-67) that the resolution of peptides on reversed phase can be profoundly influenced by the addition of appropriate counterionic reagents to a mobile phase of deflned pH, ionic strength, and water content. Retention under these conditions can be discussed in terms of ion-air associations between the ionized peptide and a counterion in the mobile phase and subsequent sorption of the complex onto the stationary phase. Alternatively, adsorption of the counterion, particularly if it is lipophilic, onto the nonpolar stationary phase may occur, and peptide retention would then be mediated by dynamic liquid-liquid ion-exchange effects. Arguments in favor of the participation of one, the other, or both of these alternative pairing-ion phenomena in ion-pair chromatography have been extensively reviewed (16, 28b, 62, 68, 68a). It can be shown (62, 68) that retention behavior in ion-pair systems can be described by... 

A modification of the liquid phase from a low pH or ionic strength to higher values induces an irreversible effect on adsorption and modification of conformation of these phosphohydrolases. 

Surfactants are used in a wide variety of applications such as ore flotation, cleaning, polymerization processes, and pharmaceuticals and agriculture. The usual role for the surfactant is to modify interfacial properties, whether they be liquid/liquid, solid/liquid, or gas/liquid interfaces. To be effective in any of these applications, however, the surfactant must adsorb strongly at the interface. In addition to its concentration at the interface, the conformation of the surfactant at the interface is also an important factor. While the influence of solution properties such as concentration, ionic strength, and pH on surfactant adsorption are well known, the properties of the other phase also exert a significant influence. 

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