A monolithic silica column has recently been widely used for HPLC separation analysis. Compared with the particle−packed column (conventional column), the monolithic silica column eluted the analyte with a smaller retention factor (k), lower pressure and satisfactory separation [1]. However, the monolithic silica column has not been widely used for the HPLC or LC/MS analysis of steroids. These ...

Corydalis yanhusuo is used widely for the treatment of gastralgia, costalgia and dysmenorrhea in Chinese medicine. The alkaloid is the main active ingredient of C. yanhusuo. Response surface methodology was applied to optimize the separation and purification process for alkaloids by AB-8 resin-packed chromatogram column. The optimal conditions were found to be as follows: height-diameter ratio ...

Herein, we demonstrate that a homogeneous catalyst can be prepared continuously via reaction with a packed-bed of a catalyst precursor. Specifically, we perform continuous proline catalyzed α-aminoxylations using a packed-bed of L-proline. The system relies on a multistep sequence in which an aldehyde and thiourea additive are passed through a column of solid proline, presumably forming a solub...

Novel packed-capillary columns for gas chromatography were developed with a thin-wall stainless-steel capillary of 1.0 mm i.d.; and rapid temperature-programmed separations have been carried out after a basic evaluation concerning the compatibility of these columns to the temperature program. With a numerical integration method, the retention of several test analytes during temperature-programm...

The high-temperature gas chromatographic (GC) separation of several semivolatile compounds is studied with a short metal capillary column packed with fibrous material, having a polydimethylsiloxane coating thereon. Taking advantage of the excellent heat-resistance of the fiber and also the combination of the surface-deactivated metal capillary, a temperature-programmed separation up to 450 degr...