摘要:

Traditional high performance liquid chromatographic (HPLC) methods are not typically used for characterization of silicones, due to a lack of absorption in the ultraviolet (UV) region of the spectrum. However, many additives in water-based, silicone formulations absorb in the UV and can be quantified using an HPLC method. Direct injection of a silicone emulsion can lead to irreversible deposition of siloxane polymer on an HPLC column and should be avoided.

ISSN:1082-6076    

DOI:10.1080/10826079608007188

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

摘要:

A simple liquid chromatographic procedure is presented for the simultaneous quantitation of three phenothiazine drugs, namely, perphenazine, trifluoperazine and triflupromazine and their sulphoxide degrades. The LC-separation was performed on a Novapak-phenyl-4 (150 × 3.9 mm id) column and a mobile phase composed of methanol + 1.5 × 10−2M sodium acetate buffer pH 6.5 (81:19, v/v). Isocratic elution and UV-detection were adopted. Satisfactory percent assay and mean recoveries with low relative standard deviations were obtained for each drug and its sulphoxide in bulk and in tablet dosage form.

ISSN:1082-6076    

DOI:10.1080/10826079608007189

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

摘要:

An HPLC analytical system is described for the separation, identification, and quantification of Peroxisomicine A1(T-514) and related anthracenonic compounds.

ISSN:1082-6076    

DOI:10.1080/10826079608007190

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

摘要:

The principal goal of this work was to investigate the liquid chromatographic retention behaviour of fluoxetine and norfluoxetine using HPLC with respect to mobile phase composition, pH, flow rate and the amount of the native β-cyclodextrin (β-CD) or the β-hydroxypropyl-cyclodextrin (HP-β-CD), added to the mobile phase. Further, it was of interest to evaluate the effectiveness of β-CD and HP-β-CD to enhance fluorescence detection of these compounds.

ISSN:1082-6076    

DOI:10.1080/10826079608007191

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

摘要:

Propofol (2,6 disopropylphenol) is a short-acting hypnotic agent, effective for the maintenance of anaesthesia when given intravenously as repeated bolus injections or as a continuous infusion. The present paper deals with the analysis of this drug in different parts of the blood. The results obtained by means of HPLC show that propofol not only variously bonds with plasma or solid blood elements, but also penetrates into the interior of blood cells.

ISSN:1082-6076    

DOI:10.1080/10826079608007192

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

摘要:

Protein sorption from raw rennet whey at pH 3.0 onto S-type (strong acid), and at pH 7.2 onto Q-type (strong base), ion exchange beads and membranes was measured. The data were used to analyze protein binding capacities, percentage recoveries, production rates, and design parameters for a commercial-scale process. Performance of S-type beads was superior to Q-type beads, but Q-type and S-type membranes performed comparably, except that the S-type membranes lost capacity during repeated cycling without cleaning, while the Q-type membranes did not. Performance of the S-type membranes was increased by microfiltration of the whey before loading, but this was partially offset by the lower protein content of the microfiltered whey. Increasing the flow rate through the cartridge increased productivity, but the percentage protein recovery decreased. This was attributed to the pore size of the membrane, which may have been too large for protein to reach the pore wall by diffusion before it passed through the membrane. A smaller pore size may increase the capture of protein and the binding capacity, but at the expense of plugging if the pores are too small.

ISSN:1082-6076    

DOI:10.1080/10826079608007193

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

摘要:

High-speed countercurrent chromatography (HSCCC) was applied to purification of fish oil ethyl esters (FOEE). The CCC separations were performed using non-aqueous two-phase solvent systems in two steps: The first purification was carried out with a hexane-acetonitrile system where 30 mL of crude FOEE was cleaned in 140 min yielding 23.1 mL of refined FOEE. The product was colorless and free of saturated fatty acid esters. The second and final purification was performed with a hexane-dichloromethane-acetonitrile (5 : 1:4, v/v/v) where 1 g of the refined FOEE was resolved into three fractions, ethyl hexadecenoate, ethyl octadecenoate and the third composed of 56.4% of ethyl docosahexaenoate and 39.3% of ethyl eicosapentenoate. The separation was completed in 145 min. However, polyunsaturated fatty acids are not resolved with this solvent system due to their low partition coefficients.

ISSN:1082-6076    

DOI:10.1080/10826079608007194

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

摘要:

A simple and partially automated method for the HPLC determination of the new anticonvulsants vigabatrin and gabapentin in serum samples from epileptic patients is described. The first step in sample pre-treatment is the precipitation of the serum proteins using an excess of acetonitrile to which two internal standards have been added. After centrifugation the supernatant fraction of the samples was placed into an autosampler of an HPLC apparatus which can be programmed with different automatic procedures for pre-injection derivatizations.

ISSN:1082-6076    

DOI:10.1080/10826079608007195

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

摘要:

Polynuclear aromatic hydrocarbons (PAHs) from smoked and broiled fish were isolated by supercritical fluid extraction (SFE), and quantitatively determined by reversed phase liquid chromatographic (RP-HPLC) methods. The SFE-method was tested first with inert matrix. As expected, the extraction of PAHs from quartz sand gave good recoveries ranging from 80 to 100 % with R.S.D. of 3–11 %. The extraction of fish material showed that methanol had to be used as a modifier, because larger PAH molecules were weakly extracted with pure CO2. The use of methanol resulted in, however, that lipophilic compounds were co-eluting in greater amounts, interfering the analysis of PAHs by HPLC - UV. That is why the extracts were purified using solid phase extraction (SPE) prior to chromatographic determination. The extraction of one sample was completed in 20 minutes, while several hours are consumed in the conventional solvent extraction methods. The sensitivity of the method used is in ppb-range, which corresponds well with the concentration of PAHs in smoked fish products.

ISSN:1082-6076    

DOI:10.1080/10826079608007196

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

摘要:

The thin layer chromatographic (TLC) retention,RM, and separation, α, on silica of esters of the natural (2R,3R)-tartaric acid, RO2C CH(OH) CH(OH) CO2R, and related 1,3-dioxolanes were studied. Twenty mobile phases were used, being selected by the previously elaborated computer program LSChrom based on the Snyder parameters strength, ε, localization,m, and polarity,P′.

ISSN:1082-6076    

DOI:10.1080/10826079608007197

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor