Fast analytical methodologies are mandatory for large scale metabolic profiling. Here, we present a thorough evaluation of different column chemistries in combination with different mobile phases for fast LC-MS urinary metabolic profiling. Three porous HILIC materials were investigated, next to core-shell C18-, XB-C18- and PFP-RPLC material. The performance of the selected column chemistries wa...

Ten new polyhydroxyolean-12-ene pentacyclic triterpenoidal saponins, named rogchaponins 1-10, were isolated from the methanolic extract of the roots of Camellia sinensis by a series of chromatographic methods (silica gel flash column and C18 MPLC followed by C18 HPLC). Their structures were established by 1D and 2D-NMR techniques along with IR and HR-TOF-MS. Rogchaponins R4 ( 4) and R5 (5) show...

The performance of isocratic separations of 11 pollutant phenols (PP) using monolithic (Chromolith RP-18e) and conventional reversed-phase 5 microm (Luna and Purospher C18) and 4 microm (Synergi C12) particulate size columns, selected from high purity silica materials, has been compared. The separations have been optimized based on a previously optimized separation in which a reversed-phase C18...

This paper describes the development of a method for the simultaneous determination of ten anticoagulant rodenticides (coumafuryl, warfarin, pindone, coumatetralyl, coumachlor, difenacoum, bromadiolone, brodifacoum, chlorophacinone and flocoumafen) in the liver and kidney based on column-switching liquid chromatography coupled with heated electrospray ionization tandem mass spectrometry. The si...

Isolated five known iridoids glycosides (Scrophuloside A, Harpagoside B, 5-hydroxyloganin, 8-O-acetylharpagide and 6-O-methyl,1-glucopyranosyl catalpol), one phenyl ethanoid glycoside (Verbascoside) and a phenyl ethanol amine (2-(4-Chlorobenzyl amino) ethanol) compound from the methanolic extract of aerial parts of Scrophularia oxysepala using by high performance liquid chromatographyare based ...

A reversed-phase high performance liquid chromatography (HPLC) technique was developed for the analysis of sphingoid bases as their biphenylcarbonyl derivatives. The sphingoid bases (0.3-500 nmol) obtained from sphingolipids after hydrolysis were quantitatively derivatized with biphenylcarbonyl chloride at room temperature for 90 min. After removal of excess reagent by partitioning, the derivat...

Column selection in reversed-phase liquid chromatography is still not a straightforward process. In this study, we have evaluated and compared the performance of several traditional C18 phases with polar-modified phases and found distinct differences in the chromatographic behavior between two groups, as well as a high degree of variability within each group. The polar-endcapped phases exhibit ...

"Hydrophobic chromatography", which is a variation of reverse phase chromatography, is applicable to the analysis of cephalosporin C derivatives, especially in fermentation broths. Unfortunately, there are no commercial C18 columns which are entirely suitable for this class of compounds. For this reason C18 columns were prepared by an in-situ bonding technique and were optimally designed for ce...

A rapid and simple method is described for the preconcentration and discrimination between the organic fraction and the labile fraction of the metals Mn, Cd, Cu, Z, V, Ni, Pb, and Fe from seawater using 8-hydroxyquinoline, which forms neutral complexes with these metals, followed by adsorption on C18 chemically bonded silica gel. The sample flow rate through the C18 column was about 4 ml min. T...