Control of adsorption and solubility in gradient high performance liquid chromatography. Part 4. Sudden-transition gradient elution of styrene/ethyl methacrylate copolymers in reversed phase mode

1994 ◽  
Vol 39 (3-4) ◽  
pp. 170-174 ◽  
Author(s):  
G. Glöckner ◽  
D. Wolf ◽  
H. Engelhardt
Keyword(s):  
High Performance Liquid Chromatography ◽  
Liquid Chromatography ◽  
High Performance ◽  
Gradient Elution ◽  
Reversed Phase ◽  
Ethyl Methacrylate ◽  
Methacrylate Copolymers ◽  
Sudden Transition

High Performance Liquid Chromatography Coupled with Radioactivity Detection: A Powerful Tool for Determining Drug Metabolite Profiles in Biological Fluids

1986 ◽  
Vol 41 (1-2) ◽  
pp. 115-125 ◽  
Author(s):  
K.-O. Vollmer ◽  
W. Klemisch ◽  
A. von Hodenberg
Keyword(s):  
High Performance Liquid Chromatography ◽  
Liquid Chromatography ◽  
High Performance ◽  
Biological Fluids ◽  
Gradient Elution ◽  
Reversed Phase ◽  
Isolation And Purification ◽  
Carbon 14 ◽  
Tracer Techniques ◽  
Metabolite Profiles

Abstract High performance liquid chromatography coupled with continuous radioactivity detection rep­resents an advancement in drug metabolism research. Using radioactive substances labelled in biologically stable positions, all metabolites can be specifically detected by radioactivity measure­ment. Thus no clean-up of biological fluids is required prior to HPLC. This can prevent artefact formation from unstable metabolites, reduces recovery problems and facilitates quantitation. Separation of highly polar and unpolar metabolites is possible in a single chromatographic run using gradient elution and reversed phase materials. This technique is also well-suited for prepara­tive isolation and purification of metabolites for subsequent structure elucidation. Various metabolite profiles of drugs labelled with carbon-14 or tritium are shown. Metabolites of the following drugs are presented: norfenefrine, etozolin, thymoxamine, naloxone, and levobunolol. We review the general methodology and report our experience with this technique. In principle, this technique may be useful for all biological systems in which tracer techniques are applied.

EVIDENCE FOR BIIIARY EXCRETION OF PHENPROCOUMON AND ITS METABOLITES IN HUMANS; IDENTIFICATION BY HIGH-PERFORMANCE LIQUID CHROMATOGRAPHY AND GAS CHROMATOGRAPHY-MASS SPECTROMETRY

1987 ◽  
Author(s):  
J X de Vries ◽  
R Raedsch ◽  
A Stiehl ◽  
U Voelker ◽  
I Walter-Sack ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Gas Chromatography ◽  
High Performance Liquid Chromatography ◽  
Liquid Chromatography ◽  
High Performance ◽  
Gradient Elution ◽  
Reversed Phase ◽  
Gas Chromatography Mass Spectrometry ◽  
Phase Gradient ◽  
Chromatography Mass Spectrometry

Recently it has been shown that in man the oral couma-rin anticoagulant phenprocoumon is eliminated up to 60-70 % in urine and 30-40 % in faeces; in urine phenprocoumon (PH) and its metabolites 7-hydroxy-(7-OH),6-hydroxy-(6-OH) and 4'-hydroxy-(4'-OH) phenprocoumon are present mainly as conjugates. No data so far were available on the biliary excretion of these compounds.We examined bile obtained from four in-patients during PH treatment; bile samples were aspirated in the duodenum at the papilla during routine diagnostic endoscopy and immediately deep frozen before analysis. Samples were extracted both untreated as well as after hydrolysis with 6-glucuronidase/aryl sulfatase and separated by reversed phase gradient elution high performance liquid chromatography (HPLC) with fluorescence detection; for confirmation, the same extracts were methylated and analysed by gas chromatography-mass spectrometry (CG-MS) (J.X.de Vries et al J Chromatogr., 338 (1985) 325). PH, 7-OH, 6-OH and 4'-OH were identified by comparison with synthetic authentic samples'''''''

scholarly journals Separation of porphyrin isomers by high-performance liquid chromatography

1983 ◽  
Vol 211 (2) ◽  
pp. 435-438 ◽  
Author(s):  
C K Lim ◽  
J M Rideout ◽  
D J Wright
Keyword(s):  
High Performance Liquid Chromatography ◽  
Liquid Chromatography ◽  
High Performance ◽  
Gradient Elution ◽  
Reversed Phase ◽  
Type I ◽  
Phase Gradient ◽  
Preparative Isolation ◽  
Type Iii ◽  
Simultaneous Separation

A reversed-phase gradient elution system is described for the simultaneous separation of the type I and type III isomers of 8-, 7-, 6-, 5- and 4-carboxylated porphyrins and isocoproporphyrins. The method, adaptable for isocratic and stepwise separation of individual groups of isomers, is also suitable for preparative isolation of pure porphyrins. The analyses of porphyrin isomers in the urine and faeces of porphyric patients are examples of applications.

scholarly journals Combined Determination of Succinic Acid and Cetylpyridinium Chloride in Medicinal Films by Gradient High Performance Liquid Chromatography

Medicina ◽  
2021 ◽  
Vol 9 (2) ◽  
pp. 75-88
Author(s):  
O. N. Dvorskaya ◽  
◽  
N. N. Nozhkina ◽  
Keyword(s):  
High Performance Liquid Chromatography ◽  
Liquid Chromatography ◽  
Succinic Acid ◽  
High Performance ◽  
Cetylpyridinium Chloride ◽  
Gradient Elution ◽  
Reversed Phase ◽  
Gradient Elution Mode

A technique has been developed based on reversed-phase high-performance liquid chromatography with diode-matrix detection for the joint determination of succinic acid and cetylpyridinium chloride in complex action medicinal films. Efficient chromatographic separation of active drug components was achieved in a gradient elution mode on a Luna C18 (2) 100A column (4.6 × 250 mm, 5 µm) using a mobile phase consisting of a 0.1% solution of phosphoric acid and acetonitrile. The detection wavelength was 210 nm for both compounds. The developed method is validated in terms of specificity, linearity, precision, accuracy and can be used to determine the authenticity and quantitative content of succinic acid and cetylpyridinium chloride in the joint presence in assessing the quality of medicinal films.

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