In the present study, an improved method termed negative-pressure cavitation extraction (NPCE) followed by reverse phase high-performance liquid chromatography (RP-HPLC) was developed for the extraction and quantification of vindoline (VDL), catharanthine (CTR), vincristine (VCR) and vinblastine (VLB) from Catharanthus roseus leaves. The optimized method employed 60-mesh particles, 80% ethanol,...

High pressure liquid chromatography (RP-HPLC) is a column chromatographic technique employing high pump to pass both mobile phase and sample mixture through stationary perform efficient separation. A C-18 with containing Acetonitrile: methanol (80: 20) was used. The flow rate 1.0ml/min. were monitored at 210 nm. retention time for Lorazepam 1.3 min. method validated linearity, accuracy, precisi...

glichkeiten. Angewandte Chemie 105: 659; Angewandte Chemie, International Edition English 32: 629. Francuskiewicz F (1994) Polymer Fractionation (Springer Lab Manual). Heidelberg: Springer Verlag. GloK ckner G (1987) Polymer Characterization by Liquid Chromatography. Amsterdam: Elsevier. GloK ckner G (1991) Gradient HPLC of copolymers and chromatographic cross fractionation. Berlin: Springer Ve...

Qualification and calibration of high performance liquid chromatography (HPLC) chromatographs is a regulatory requirement, but how proscriptive should guidance be?

We studied the metabolism of A14l-insulin in intact human fibroblasts using high performance liquid chromatography (HPLC) to detect and separate its early degradation products. The high resolving power of HPLC enabled us to separate what has been considered "intact insulin" by Sephadex G-50 chromatography or TCA precipitability into two additional peaks that had decreased biochemical properties...

the efficacy of activation methods and coupling were studied in the context of performance in batch and fixed bed binding experiments utilizing cell culture fluids or blood plasma as feedstock. conclusions were drawn regarding selection of solid phase according to pore size, rigidity, ph stability, chemistry of derivation and activation, and gross concentration of immobilized ligand required fo...

background: a simple and sensitive high performance liquid chromatography-electrospray ionization mass spectrometry method has been evaluated for the assignment of clonidine hydrochloride in human plasma. methods: the mobile phase composed of acetonitrile-water 60:40 (v/v) and 0.2% formic acid 20 µl of sample was chromatographically analyzed using a repacked zorbax-xdb-ods c18 column (2.1 mmx30...

The first hyphenation of high performance liquid chromatography (HPLC), electrochemical online oxidation and mass spectrometry (MS) is described. Ferrocenecarboxylic acid esters of various alcohols and phenols have been synthesized, separated by reversed-phase HPLC and oxidized (ionized) coulometrically prior to single quadrupole MS analysis using electrospray ionization (ESI) and atmospheric p...

A new hydroxycinnamoyl polyamine derivative, N,N',N"-triferuloylspermidine (= (E)-N-(4-aminobutyl) -3,3',3"-tris(4-hydroxy-3-methoxyphenyl)-N,N',N"- (butane-1,4-diyl)tris [prop-2-enamide]) (1) was detected in the H2O/MeOH extract of pollen from Hippeastrum x hortorum. The compound was identified by on-line-coupled high-performance liquid chromatography and atmospheric-pressure chemical-ionizati...