Mobile Phase Exchange Process in Stepwise Elution Liquid Chromatography Analyzed by Chromato-Videoscope.

High speed gradient elution reversed-phase liquid chromatography.

A major disadvantage of gradient elution in terms of speed results from the need to adequately re-equilibrate the column. This work distinguishes two states of re-equilibration: (1) run-to-run repeatability and (2) full equilibration. We find that excellent repeatability (+/-0.002 min in retention time) is achieved with at most 2 column volumes of re-equilibration whereas full equilibration can...

Effect of mobile phase composition on the overall elution process in thin-layer chromatography

Automated chromatography for stepwise elution of complex lipids.

An automated column-chromatographic system for stepwise elution of lipids is described. The automation is achieved with commercially available snap-on modules and Teflon valves.

Improved peptide elution time prediction for reversed-phase liquid chromatography-MS by incorporating peptide sequence information.

We describe an improved artificial neural network (ANN)-based method for predicting peptide retention times in reversed-phase liquid chromatography. In addition to the peptide amino acid composition, this study investigated several other peptide descriptors to improve the predictive capability, such as peptide length, sequence, hydrophobicity and hydrophobic moment, and nearest-neighbor amino a...

Stepwise pH-gradient elution for the preparative separation of natural anthraquinones by multiple liquid-liquid partition.

Preparative-scale separation of substituted anthraquinones by multiple liquid-liquid partition was studied using isopropylmethyl ketone (IMK)/aqueous phosphate buffer (aq.) as the solvent system and the Hietala apparatus with 100 partition units as the partition equipment. The lower (aq.) phase was chosen as mobile, while the upper (IMK) phase remained stationary. Hence, the principle of stepwi...