摘要:

We have examined the most favorable conditions for the agarose gel electrophoretic separation of RNA from several C-type RNA viruses. The influence of such factors as agarose concentration, temperature of gelation and the temperature and duration of electrophoresis were investigated. In contrast to polyacrylamide-agarose gel electrophoresis (PAGE), the resolving powers of agarose gels were not affected by the gelation temperature or the temperature of electrophoresis. The molecular weight values obtained for different viral RNA's were reproducible and did not differ significantly from those obtained using PAGE. Agarose gels have the added advantages of being easy to prepare and are non-toxic.

ISSN:0003-2719    

DOI:10.1080/00032717908055705

出版商:Taylor & Francis Group    

年代:1979

数据来源: Taylor

摘要:

In view of the persistent controversy about the volatility of chromium in biologic materials, we determined the element by neutron activation analysis in three reference materials before and after dry ashing up to 450°C. We obtained the following mean values: 0. 364/μg/g and 0. 362 μg/g (Bowen's kale), 0. 0806 μg/g and 0. 0789 μg/g (NBS bovine liver), 2. 043 μg/g and 2. 094 μg/g (NBS brewers yeast). We conclude that chromium does not volatilize significantly in our experimental conditions of drying and ashing.

ISSN:0003-2719    

DOI:10.1080/00032717908055706

出版商:Taylor & Francis Group    

年代:1979

数据来源: Taylor

摘要:

A method has been developed whereby low levels of mercury can be determined in biological samples. The sample is burned in an air stream and the mercury vapors are collected in a cold trap and determined by flameless atomic absorption spectroscopy.

ISSN:0003-2719    

DOI:10.1080/00032717908055707

出版商:Taylor & Francis Group    

年代:1979

数据来源: Taylor

摘要:

Steroids, including cortisone, Cortisol, aldosterone, cortol, preg-nanediol, androsterone and 4-androsten-3, 17-dione can be ionized directly, without derivative formation, by plasma desorption ionization to give characteristic mass spectra. The ion products, with isobutane as the reagent gas, indicate the nature of the functional groups and the molecular formula; the spectra are similar to those obtained by chemical ionization methods.

ISSN:0003-2719    

DOI:10.1080/00032717908055708

出版商:Taylor & Francis Group    

年代:1979

数据来源: Taylor

摘要:

An original method of preparation of enzyme collagen membranes has been developed which enables the asymmetrical coupling of multienzymatic systems working in sequence. One or several enzymes are immobilized on one face of the acyl-azide activated membranes, another enzyme being bound on the other face. When the first enzymatic face is exposed to the adequate reaction mixture, the products diffuse through the collagen membrane and act as substrates for the enzyme present on the other side. This possibility has been applied to the design of new and polyvalent multienzyme electrodes.

ISSN:0003-2719    

DOI:10.1080/00032717908055709

出版商:Taylor & Francis Group    

年代:1979

数据来源: Taylor

摘要:

A method is described for assessing radiochemical purity of compounds measured by radioimmunoassay. This method is applicable in cases when chromatography is used prior to the radioimmunoassay proper. In individual fractions of the chromatographic zone containing the compound assayed, both radioactivity (e. g. in DPM) and mass (e. g. in pg) are measured. The measurement of mass is performed using radioimmunoassay. Radiochemical purity is assumed, if the radioactivity/mass ratio (specific activity) in individual fractions of the zone is constant. The constancy of specific activity is tested statistically using a regression analysis. A radioimmunoassay of progesterone in a blood plasma pool collected during the follicular phase of the menstrual cycle was used to demonstrate the practical features of the assessment of radiochemical purity. Radiochemical pure progesterone could be obtained only after repeated chromatography. Purification to radiochemical purity resulted in a significantly decreased estimate of progesterone contents in the plasma pool investigated. A value of 344 pg/ml was obtained, in contrast to the value of 422 pg/ml found prior to the repeated chromatography. The former value can be considered an accurate and valid estimate.

ISSN:0003-2719    

DOI:10.1080/00032717908055710

出版商:Taylor & Francis Group    

年代:1979

数据来源: Taylor

摘要:

A new absorptiometric procedure for the determination of quintomycin sulphate in complex galenical mixtures is proposed, based on the reaction of the sample compound with a mineral acid-containing phloroglucinol solution. Absorbance readings at 448 nm obey Lambert-Beer's law within the concentration range from 4. 0 to 32. 0 μg ml−1. The method is operationally simple and has a good precision and an adequate selectivity.

ISSN:0003-2719    

DOI:10.1080/00032717908055711

出版商:Taylor & Francis Group    

年代:1979

数据来源: Taylor

摘要:

During the present study, the TLC separation of some closely related 3-hydroxy-6H-benzofuro [2, 3-C] [1] benzopyran-6-ones and their basic ethers have been carried out.

ISSN:0003-2719    

DOI:10.1080/00032717908055712

出版商:Taylor & Francis Group    

年代:1979

数据来源: Taylor

摘要:

A liquid membrane Ag+-selective electrode of our construction and a commercial solid membrane Ag+/S2--selective electrode were used for the determination of thiobarbiturates by potentiometrie titration with AgNO3solution or by direct potentlometry. The potentio-setrio data correlated vd. th IR spectra allowed the elucidation of the reaction mechanism.

ISSN:0003-2719    

DOI:10.1080/00032717908055713

出版商:Taylor & Francis Group    

年代:1979

数据来源: Taylor

摘要:

A method has been developed to simultaneously determine aspirin, salicylic acid, salicyluric acid, and gentisic acid concentrations in human plasma and urine. An extraction and dry-down step prepare the sample for resolution by reverse-phase high pressure liquid chromatography. The column effluent is monitored by both ultraviolet absorbance and fluorescence to optimize sensitivity and specificity for the compounds of interest.

ISSN:0003-2719    

DOI:10.1080/00032717908055714

出版商:Taylor & Francis Group    

年代:1979

数据来源: Taylor