Standard‐free kinetic calibration for rapid on‐site analysis by solid‐phase microextractionJournal of Separation Science - Tập 31 Số 6-7 - Trang 1167-1172 - 2008
Gangfeng Ouyang, Jibao Cai, Xu Zhang, Hui Li, Janusz Pawliszyn
AbstractIn this study, a new calibration method, standard‐free kinetic calibration, is proposed for rapid on‐site analysis by solid‐phase microextraction (SPME), based on the diffusion‐controlled mass transfer model and equilibrium extraction. With this calibration method, all analytes can be directly calibrated with only two samplings. The feasibility of this cali...... hiện toàn bộ
Preparative isolation of pseudolaric acids A and B, and their glucosides from the root bark of Pseudolarix kaempferi using high‐speed counter‐current chromatographyJournal of Separation Science - Tập 32 Số 2 - Trang 309-313 - 2009
Quan‐Bin Han, Lina Wong, Fanny Lai, Nian‐Yun Yang, Jing‐Zheng Song, Chun‐Feng Qiao, Hong‐Xi Xu
AbstractIn order to provide the chemical markers for the quality control of herbal medicines, four diterpenoids, pseudolaric acids A and B (PAA and PAB), and their glucosides were isolated from the methanol extract of the Chinese herb Pseudolarix kaempferi using high‐speed counter‐current chromatography (HSCCC). The diphase solvent system...... hiện toàn bộ
Simple 2D‐HPLC using a monolithic silica column for peptide separationJournal of Separation Science - Tập 27 Số 10-11 - Trang 897-904 - 2004
Hiroshi Kimura, Tetsuya Tanigawa, Hironobu Morisaka, Tohru Ikegami, Ken Hosoya, N. Ishizuka, Hiroyoshi Minakuchi, Kazuki Nakanishi, Mitsuyoshi Ueda, Karin Cabrera, Nobuo Tanaka
AbstractSeparation of peptides by fast and simple two‐dimensional (2D)‐HPLC was studied using a monolithic silica column as a second‐dimension (2nd‐D) column. Every fraction from the first column, 5 cm long (2.1 mm ID) packed with polymer‐based cation exchange beads, was subjected to separation in the 2nd‐D using an octadecylsilylated (C18) mon...... hiện toàn bộ
Preparation and HPLC applications of rigid macroporous organic polymer monolithsJournal of Separation Science - Tập 27 Số 10-11 - Trang 747-766 - 2004
František Švec
AbstractRigid porous polymer monoliths are a new class of materials that emerged in the early 1990s. These monolithic materials are typically prepared using a simple molding process carried out within the confines of a closed mold. For example, polymerization of a mixture comprising monomers, free‐radical initiator, and porogenic solvent affords macroporous materia...... hiện toàn bộ
HPLC retention behavior on hydride‐based stationary phasesJournal of Separation Science - Tập 30 Số 5 - Trang 637-647 - 2007
Joseph J. Pesek, Maria T. Matyska, Susan Larrabee
AbstractTwo stationary phases attached to a silica hydride surface, cholesterol and bidentate C18, are investigated with a number of pharmaceutically related compounds in order to illustrate the various retention mechanisms that are possible for these bonded materials. The test solutes range from hydrophilic to hydrophobic based on log P ...... hiện toàn bộ
Methacrylate monolithic columns for capillary liquid chromatography polymerized using ammonium peroxodisulfate as initiatorJournal of Separation Science - Tập 26 Số 18 - Trang 1623-1628 - 2003
Petra Holdšvendová, Pavel Coufal, Jana Suchánková, Eva Tesařová, Zuzana Bosáková
AbstractFour methacrylate ester‐based monolithic columns for capillary liquid chromatography (CLC) were prepared by radical polymerization with ammonium peroxodisulfate (3 columns) and by thermal initiation (1 column). The polymerization mixture consisted of butyl methacrylate (BMA) and ethylene glycol dimethacrylate (EDMA), propan‐1‐ol, butane‐1,4‐diol, water, and...... hiện toàn bộ