摘要:

Five plant tocopherols were separated by normal phase high performance liquid chromatography (HPLC) on aminopropylsilica or diol-bonded silica with fluorescence detection. HPLC characteristics of these compounds were studied under various mobile phase conditions. Mobile phases employed binary solvent systems comprising a hydrocarbon and an alcohol, an ether or an ester. Separation factors (α) of adjacent ring-methylated tocol components were determined.

ISSN:1082-6076    

DOI:10.1080/10826079608005516

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

摘要:

A method of isolation and complete separation of lipids from natural sources into classes and species is reported which combines our previously published techniques with new techniques described in this article for the first time. Pigments are separated from crude total lipid extracts with two successive TLC systems: a) petroleum ether/benzene/glacial acetic acid (30:70:2) and b) acetone/methanol/water (40:20:1). Pigment-free total lipids are separated on a silicic acid column into neutral, glyco- and phospholipids. Neutral, glyco- and phospholipids are separated into classes and species by suitable HPLC methods.

ISSN:1082-6076    

DOI:10.1080/10826079608005517

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

摘要:

A simple mixture of anthocyanins was analysed by CZE, using a standard silica capillary with a pH 8 borate running buffer. Generally, the anthocyanins separated according to the nature of the aglycone and degree of glycosylation. A concentrated injection solution was required for detection at 580 nm, due to the small proportion of coloured quinonoidal base in the anthocyanin equilibrium mixture at this pH, the small injection volume and the short detector path-length used in this technique.

ISSN:1082-6076    

DOI:10.1080/10826079608005518

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

摘要:

Acetonitrile has been investigated as the organic modifier for the reverse phase separation of twenty-two sulphonamides and three commonly used dihydrofolate reductase inhibitors. Isocratic analyses indicate that 10% acetonitrile is approximately isoeluotropic with 16% methanol. This allows a comparison of selectivities. Relative to methanol, in gradient elution involving acetonitrile only, unfavourable changes in the relative retentions of some pairs of analyses outweighed the advantages of favourable selectivities. Insertion of acetonitrile into methanol gradients did not produce the improved separations expected. However, the imposition of a program of reduced flow upon an established methanol gradient demonstrated significantly increased efficiencies in the front half of the chromatogram. This permitted the resolution of the first thirteen compounds, including the difficult-to-separate pair of sulphathiazole and sulphapyridine.

ISSN:1082-6076    

DOI:10.1080/10826079608005519

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

摘要:

The application of capillary ion electrophoresis to the separation and determination of chromium (VI), molybdenum (VI) and vanadium (V) with direct on-column UV detection at 254 nm is described. Using a cathodic injection and anodic detection scheme, Cr(VI), Mo(VI) and V(V) were separated in about 4 min in a fused silica capillary column, with a phosphate buffer of pH 12.0, at an applied voltage of 15 KV, followed by direct UV detection. An electro-osmotic flow modifier, namely a cetyltrimethylammonium bromide (CTAB), is necessary to shorten the migration times of these ions. Incorporating citrate into the electrophoretic buffer markedly improves the sensitivity and efficiency.

ISSN:1082-6076    

DOI:10.1080/10826079608005520

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

摘要:

In order to investigate the formation of organic salts of drugs, two new salts of pindolol were precipitated using benzoic acid and 2-methoxyphenylacetic acid. The reversed-phase high-performance liquid chromatographic (HPLC) method was developed for the determination of the mole ratio of the salt components. The method permits the simultaneous quantitation of the cationic and anionic parts of the salts prepared. The method was validated with respect to linearity and precision of the chromatographic run and the assay. Also, the precisions at the lowest and the highest levels of the linearity curves were tested. The system suitability was studied by calculating the chromatographic parameters, such as capacity factor (k′), number of theoretical plates (N), tailing factor (T) and resolution (R) between pindolol and organic acids used.

ISSN:1082-6076    

DOI:10.1080/10826079608005521

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

摘要:

Many plants and their products are used as sources of pharmaceuticals and as ingredients of traditional medicines, and are of value in new drug discovery. In this study, we fractionated the whole black seed proteins into twenty fractions by using Rotofor. The pH range was recorded as (2.63 to 10.46). Protein concentration range and percent protein recovered were 0.305 to 1.01 mg/mL and 5 to 17% respectively. A single 4 hr Rotofor run at 12W in the pH 3 to 10 range yielded well separated proteins into twenty fractions. Black seed (N. sativa) proteins isolated range between 200 kDa and 14 kDa when these fractions were analyzed by sodium dodecyl sulphate polyacrylamide gel electrophoresis.

ISSN:1082-6076    

DOI:10.1080/10826079608005522

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

摘要:

A rapid, specific and reliable technique has been developed for the determination of piperacillin in biological samples by High Performance Liquid Chromatography.

ISSN:1082-6076    

DOI:10.1080/10826079608005523

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

摘要:

A highly sensitive and selective reversed-phase high performance liquid chromatography (RP-HPLC) with fluorescence detection for topotecan (SK&F 104864A) trace analysis is presented. Topotecan is the prototype of a novel class of antitumor agents, which exert their activities exclusively by inhibition of cellular topoisomerase I. The analytical method is based on an efficient HPLC separation using a Zorbax® StableBond® narrow bore (150 × 2.1 mm i.d.) C8column (particle size 5 mm). A secondary-retention phenomenon was noticed during the studies, however, and the problem was solved by adding 0.1% (v/v) triethylamine. Zorbax® StableBond® columns represent the new class of silane-modified silica, and have proved to be stable at least four months with continuously analyzed samples containing bleach and hydrogen peroxide. Column effluents were monitored via fluorescence with the excitation wavelength set at 225 nm and the emission wavelength at 520 nm. The limit of quantification (LOQ) for topotecan was 0.2 ng/mL. Linear response was observed for concentration of topotecan from 0.2 to 20 ng/mL. The method not only provided sensitive, precise and accurate support to photolysis, biodegradation and deactivation treatment system studies but also reduced the organic solvent waste by two-thirds as compared to conventional HPLC columns (4.6 mm i.d.).

ISSN:1082-6076    

DOI:10.1080/10826079608005524

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

摘要:

Several extraction methods and column types were compared, with respect to extraction and separation efficiency of 14 additives from soy sauce, sugared fruit and dried roast beef, by paired-ion liquid chromatography. Results showed that the application of a Sep-Pak C18cartridge was the best method for extraction, because it resulted in higher recovery than those given by acetone extraction and steam distillation. The purification of acetone extract by a Sep-Pak silica gel cartridge can result in recovery loss. Monomeric column was superior to polymeric column for simultaneous separation of preservatives, antioxidants and sweeteners. The capacity factor (k′) of each additive was also determined.

ISSN:1082-6076    

DOI:10.1080/10826079608005525

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor