Studies on the stabilization of reversed phases for liquid chromatography

Chromatographic activity of residual silanols of alkylsilane derivatized silica surfaces

“…It was proposed that bulky substituents on the silicon atom of octadecylsilanes would increase the chromatographic lifetime of column packings [5,6]. Indeed, Kirkland et al have shown that phases with isobutyl substituted C18 silane groups exhibit a longer lifetime in low-pH aqueous organic mobile phases than their conventional methyl substituted analogues [7].…”

Determination of the Hydrophobicity of Local Anesthetic Agents

“…However, they suffer from two disadvantages: First, they have a limited usable pH range, typically pH 2-8. Below pH 2, the bonded phase is susceptible to hydrolysis (32). Above pH 8, hydroxide ions (OH Ϫ ) can attack and dissolve the silica, which causes the collapse of the packed bed and a catastrophic loss of efficiency (33).…”

Development of an accelerated low-pH reversed-phase liquid chromatography column stability test

“…The differences in low-pH stability are due to differences in the type of C 18 ligand used for the bonding, the presence or absence of an endcap, the bonding density of the phase and the characteristics of the underlying silica. [2,5,[21][22][23][24]. A run time of 90 min is used and the retention changes for the alkylbenzenes are monitored.…”