The HPLC-SPE-NMR technique was used for the analysis of a root-bark extract of Croton membranaceus. The components of the extract were separated on an analytical-size reversed-phase HPLC column, the chromatographic peaks were trapped on SPE (solid-phase extraction) cartridges after post-column dilution of the eluate with water and the compounds were eluted from the cartridges with acetonitrile-...

Hollow fibre cell fishing with HPLC (HFCF-HPLC) based on the human ovarian cancer cell line SKOV-3, human renal tubular cell line ACHN or hepatoma cell line HepG-2 was employed to screen active groups of coumarin and volatile oil in Radix angelicae sinensis, Radix angelicae dahuricae and Fructus citri sarcodactylis. Simultaneously, hollow fibre liquid phase microextraction with HPLC (HFLPME-HPL...

We have purified and further characterized a histamine releasing factor (HRF) derived from human mononuclear cells using gel-filtration HPLC, reverse-phase HPLC, anion exchange chromatography, and elution from SDS gels after electrophoresis. Considerable heterogeneity is seen, far exceeding that published in prior reports. Gel filtration HPLC yielded a major peak at molecular weight 30,000 and ...

A simple preparation process of alkylamide phase for reversed-phase HPLC (RP-HPLC) is described. The process includes aminopropyltrimethoxysilane firstly reacted with octanoyl chloride, then the intermediate was coupled onto porous silica. The resultant bonded silica has a reproducible ligand surface concentration and homogenous bonded ligand distribution on the porous silica. Characterization ...

was performed in both direct analysis of MSB and analysis of MN by converting MSB to MN with sodium carbonate. GC-FID method was carried out on the HP-5 capillary column GC-FID and HPLC-DAD methods were developed for determination of menadione (MN) and menadione sodium bisulphite (MSB). By means of each method, quantitative analysis of MSB in commercial pharmaceutical using nitrogen gas. HPLC-D...

This study presents an HPLC method for simultaneous analysis of astaxanthin and its carotenoid precursors from Xanthophyllomyces dendrorhous. The HPLC method is accomplished by employing a C18 column and the mobile phase methanol/water/acetonitrile/ dichloromethane (70:4:13:13, v/v/v/v). Astaxanthin is quantified by detection at 480 nm. The carotenoid precursors are identified by LC-APCI-MS and...

The single biggest problem with solution-phase H/D exchange as a mass spectrometric probe of surface exposure in a protein (or protein complex) is back-exchange of H for D after the initial H/D exchange has been quenched. Back-exchange results in loss of pertinent data and also greatly hampers data analysis. Previously, very fast, cold (0-4 degrees C) HPLC was performed to help reduce back-exch...

HPLC and gel permeation chromatographic (GPC) characterization of complex phenol-formaldehyde resins is described. Reversed-phase HPLC fingerprints the phenolic monomers, dimers and some oligomers. The molecular masses of these phenolic compounds were determined using an ion trap mass spectrometer. GPC analyzes tetrahydrofuran-soluble phenolic polymers beyond HPLC capability. The molecular mass...

An azobenzene-modified gamma-cyclodextrin stationary phase (Az gamma-CDSP) was prepared and its photo- and temperature-responses for the retention of perylene and pentacene were investigated using a mixture of methanol and water as the mobile phase in micro-HPLC. The retention of perylene slightly increased, whereas that of pentacene significantly decreased by UV light irradiation to Az gamma-C...