Influence of column parameters on peak broadening in high-pressure liquid chromatography

Fast analysis in liquid chromatography using small particle size and high pressure

“…Other chromatographic parameters are also influenced by the pressure drop; the plate number per time unit (N/t 0 ) [54,58] and the separation impedance (E) that describes the best compromise in terms of speed, efficiency, and pressure drop as described by Eq. (7).…”

Stationary Phases

“…Zirconia is stable in a very wide pH range (pH [1][2][3][4][5][6][7][8][9][10][11][12][13][14], but zirconia surface has relatively low reactivity (more difficult to bond different functional groups to the surface), which significantly limits a selection of available stationary phases.…”

“…Halasz and Naefe [9] and Majors [10] suggested that if the distribution is not wider than 40% of the mean, then acceptable flow resistance and column efficiency can be obtained. The narrower the particle size distribution, the better and the more reproducibly the columns could be packed.…”

“…Chemical modification of hydroxylated surface of base material in more than 90% of commercially available HPLC stationary phase is performed by its reaction with alkylchlorosilanetype modifiers, reaction (3)(4)(5)(6)(7)(8)(9). HCl is generated as a byproduct, and typically a scavenger for HCl is employed in the synthesis.…”

“…On the silica surface, silanols can react with alcohols forming Si-O-R bonds, reaction (3)(4)(5)(6)(7)(8)(9)(10). This type of reaction allows for a very high bonding density, but hydrolytic cleavage of Si-O-R bonds is relatively high and this material is not practically applicable for HPLC support.…”