摘要:

A method is described for measuring physicochemical quantities in liquid and liquid/solid systems by means of HPLC instrumentation. It has been applied with benzene as analyte, chloroform or acetonitrile as liquid solvents, and silica gel as solid phase stuck on the internal wall of a cylindrical tube.

ISSN:1082-6076    

DOI:10.1081/JLC-100101832

出版商:Taylor & Francis Group    

年代:2000

数据来源: Taylor

摘要:

An adaptability of countercurrent chromatographic data to Van Deemter equation (H = A + B/u + Cu) is examined under a fixed volume of the stationary phase. Three test samples, epigallochatechin gallate (EGCG), gallocatechin-gallate (GCG), and epicatechin gallate (ECG) were separated using a two-phase solvent system of n-hexane/ethyl acetate/water (3.5:1:10, v/v/v) at various linear flow rates (u).

ISSN:1082-6076    

DOI:10.1081/JLC-100101833

出版商:Taylor & Francis Group    

年代:2000

数据来源: Taylor

摘要:

In reversed-phase mode, chromatographic retention is investigated thermodynamically for an enantiomeric pair on an amylose-derivative bonded phase. Ehthalpies and entropies of solute transfer (mobile to stationary phase) are calculated from retention data by evaluation of van't Hoff plots.

ISSN:1082-6076    

DOI:10.1081/JLC-100101834

出版商:Taylor & Francis Group    

年代:2000

数据来源: Taylor

摘要:

A very sensitive HPLC method for the determination of total glutathione (GSH) and γ-glutamyl-cysteine (γ-Glu-Cys) content in cell lysates is presented. It is based on a precolumn derivatization witho-phthalaldehyde (OPA) using tris(2-carboxyethyl)-phosphine (TCEP) as a reducing agent. Separation of the peptide derivatives is carried out by reversed-phase chromatography on a C18 column, followed by spectrofluorimetric detection. The fluorescence response of GSH and γ-Glu-Cys derivatives is linear over a range of 0.05 to 100 μM and 1 to 25 μM, respectively, with good precision. The detection limits approach 26 fmol and 60 fmol on column, respectively. In contrast the detection limit for GSH in the presence of DTT, which is often used as the reducing agent, is 250 fmol GSH on column. The results for the GSH concentration of cell lysates are in agreement with a radiotracer method based on metabolic labeling of GSH with [35S]-Cys.

ISSN:1082-6076    

DOI:10.1081/JLC-100101835

出版商:Taylor & Francis Group    

年代:2000

数据来源: Taylor

摘要:

This study investigated the effects of salt in a SynChropak column using peptides which are structurally simpler than proteins. Contrary to the established explanation of salt type by molal surface tension increment, the study attempted to explain salt effects by two retention parameters, S and log kw. S was considered to be related to surface tension effect, log kwto salting in effect. From the dependence of S and log kwon temperature and the stationary phase ligand type, these parameters turned out to be useful in explaining the characteristics of hydrophobic interaction chromatography (HIC) which are different from those of reversed phase chromatography (RPC).

ISSN:1082-6076    

DOI:10.1081/JLC-100101836

出版商:Taylor & Francis Group    

年代:2000

数据来源: Taylor

摘要:

A capillary zone electrophoresis method was developed and validated for simultaneous separation of streptomycin (STM) and dihydrostreptomycin (DHS) with direct UV detection at 205 nm. Good selectivity was obtained within a short analysis time.

ISSN:1082-6076    

DOI:10.1081/JLC-100101837

出版商:Taylor & Francis Group    

年代:2000

数据来源: Taylor

摘要:

Because ifosforamide mustard (IFM) is the active alkylating metabolite of ifosfamide (IFO) it is of particular interest in the pharmacokinetic analysis of patients undergoing IFO treatment. This paper presents an assay for the simultaneous determination of IFM and IFO after derivatization with diethyldithiocarbamate (DDTC), subsequent liquid-liquid extraction of the plasma with acetonitrile (AcN) and using reversed phase high performance liquid chromatography (RP-HPLC) with ultra-violet (UV) detection at 276 nm. Structural confirmation of the analytes was accomplished using mass spectrometry (MS).

ISSN:1082-6076    

DOI:10.1081/JLC-100101838

出版商:Taylor & Francis Group    

年代:2000

数据来源: Taylor

摘要:

This paper describes an HPLC procedure for the determination of tocopherols and tocotrienols in crude and edible vegetable oils. The sample preparation only involves a dissolution of the oil inn-hexane and filtration. The chromatographic separation was achieved using a normal phase column LiChrosorb SI 60 (5 μm; 25.0 × 0.4 cm). Isocratic elution was carried out usingn-hexane : 2-propanol (99.7:0.3). The effluent was monitored by using diode-array and fluorimetric detectors.

ISSN:1082-6076    

DOI:10.1081/JLC-100101839

出版商:Taylor & Francis Group    

年代:2000

数据来源: Taylor

摘要:

An isocratic technique was developed for the analysis of leuprolide acetate by high performance liquid chromatography (HPLC) using 220 nm UV detection, C18MICROSORB-MVTMcolumn (4.6 mm × 15 cm), mobile phase (0.03 M, 77% dibasic ammonium phosphate buffer: 23% acetonitrile), and 2.0 mL/min flow rate.

ISSN:1082-6076    

DOI:10.1081/JLC-100101840

出版商:Taylor & Francis Group    

年代:2000

数据来源: Taylor

摘要:

V. album(Loranthaceae)hasbeen utilized for the treatment of various diseases such as hypertension,arteriosclerosis, and cancer, either alone or in combination with other plantextracts in modern medicine. In this study, qualitative and quantitative determinationsof syringin contents ofViscum albumL.ssp.albumsamples, collected from ninedifferent host plants, were carried out by using HPLC.

ISSN:1082-6076    

DOI:10.1081/JLC-100101841

出版商:Taylor & Francis Group    

年代:2000

数据来源: Taylor