Liquid Chromatography:  Theory and Methodology

Retention and selectivity tests of silica‐based and metal‐oxide bonded stationary phases for RP‐HPLC

“…Silica-based stationary phases with pore size 60 -300 and non-polar organic ligands (such as octyl, octadecyl, or phenyl groups) attached by siloxane bonds ( -Si -OSi -C -) to the surface are applied most frequently in RP-LC separations [6,7], because of excellent chromatographic efficiency and mechanical strength of silica, which allows porous particles with very large surface areas (typically 60 -500 m 2 N g -1 ) to be used at high operating pressures [7,8]. However, silica-bonded phases show limited thermal and pH stability [9,10], and residual silanol group activity affects negatively the retention and peak symmetry of basic analytes [11,12].…”

Resolution of Racemic N-Acyl-1-arylaminoalkanes on a (3,5-Dinitrobenzoyl)phenylglycinol-Derived High Performance Liquid Chromatography Chiral Stationary Phase

“…Flash column chromatography on silica gel (mixed eluant of hexane and ethyl acetate) afforded a yellowish solid product (1.40 g, 42%), m.p., 162-164°C. 1 In a 100-ml round-bottom flask were added 3.70 g of 5-m silica gel and 50 ml toluene. From the resulting slurry, water was removed azeotropically by using a DeanStark trap.…”

“…Today, resolution of racemates on chiral stationary phases (CSPs) is quite common because various CSPs are available (1). Among others, Pirkle-type CSPs have been known to resolve racemates by forming two energetically different transient diastereomericcomplexes with two enantiomers (2).…”

Identification of factor C protein fromStreptomyces griseus by microelectrospray mass spectrometry

“…9,10 In the case of isolated biological samples where the sample amount is extremely low, capillary chromatography 11 -17 is used. A fused-silica capillary column with an inner diameter of 75-320 µm is applied for the separation of peptide mixtures.…”