Library

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    Pre-chromatographic derivatization of samples for (HP)TLCBased on a paper read at the second international Symposium of Instrumental Thin-layer Chromatography, May 1982, Interlaken. Switzerland. (1982)
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 5 (1982), S. 534-538 
    Details
    ISSN: 0935-6304
    Keywords: Thin-layer chromatography, (HP)TLC ; Pre-chromatographic derivatization ; Quantitation of estriol, cortisol, selenium ; Biological matrix ; Water analysis ; Ready-for-use column extraction ; Fluorescence enhancement ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jhrc.1240051004
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Quantitative HPTLC determination of selenium (1986)
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 9 (1986), S. 224-235 
    Details
    ISSN: 0935-6304
    Keywords: Thin-layer chromatography, HPTLC ; Biological matrices ; Fluorimetric detection ; Selenium ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The present determination of selenium in biological matrices by HPTLC with in situ fluorimetric detection is an accurate alternative method, comparable to other established methods such as photometry, polarography, neutron activation, or X-ray fluorescence analysis, gas chromatography, and atomic absorption spectrometry.The excellent sensitivity of this procedure is proved by the detection limit of 250 fg of selenium per spot (using purified 2,3,1-naphthoselenodiazole). The oxidation of organic matrices, applying a novel digestion procedure, may be carried out with little instrumental expenditure.Sample preparation steps, such as the oxidation of selenium to Se (VI) and subsequent reduction to Se (IV) do not lead to significant random or systematic errors, nor does the digestion step, if an optimized procedure is used.A recovery rate of 103% and nearly parallel calibration curves for digested selenocysteine standards compared with spiked human serum samples demonstrate the accurate quantitative preparation of a biological matrix. Any interfering metal ions can be masked by addition of chelate-forming reagents.
    Additional Material: 24 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jhrc.1240090406
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Potentiometric method for subatrate analysis using immobilized NAD+-dependent oxidoreductase enzymes (1979)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 21 (1979), S. 1905-1915 
    Details
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Two coenzyme-dependent oxidoreductases, glucose dehydrogenase and alcohol dehydrogenase, were immobilized in polyacrylamide gel over a platinum grid matrix and used as enzyme electrodes to measure their substrate concentrations in buffered aqueous solutions. The immobilized enzymes were used to oxidize their substrates in the presence of NAD+. Ferricyanide was used as the redox mediator and electroactive specific. The determinations of glucose and ethenol were utilized to demonstrate and evaluate the performance of the system. The described methodology should be readily applicable to the analysis of numerous other substrates of coenzyme-dependent oxidoreductases.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bit.260211103
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Role of platinum black in a bio-fuel cell using glucose or hydrogen as fuel source (1978)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 20 (1978), S. 1687-1689 
    Details
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bit.260201016
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Immobilized enzyme electrodes for the potentiometric measurement of glucose concentration: Immobilization techniques and materials (1979)
    Hoboken, NJ : Wiley-Blackwell
    Journal of Biomedical Materials Research 13 (1979), S. 921-935 
    Details
    ISSN: 0021-9304
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine , Technology
    Notes: Glucose oxidase, catalase, and bovine serum albumin were co-immobilized with glutaraldehyde around a platinum screen or around a single platinum - iridium wire. The potential difference between this dual enzyme electrode and a Ag/AgCl reference electrode was proportional to the logarithm of the glucose concentration over the range from 10 to about 150 mg glucose per 100 ml in buffered solution at pH 7.4 and 37°C. The enzyme electrode responded in serum only if coated with a semipermeable film, such as cellulose acetate, to exclude serum macromolecules. The potentiometric results were similar to those obtained with the two enzymes co-immobilized in polyacrylamide gel around a platinum screen or with only one of the enzymes, glucose oxidase, covalently coupled to a platinum screen. The results so far suggest that these potentiometric enzyme electrodes may have sufficient specificity for glucose for development of a continuous in vivo glucose sensor.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jbm.820130610
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Thin-layer chromatography - the forgotten alternative for the quantitative determination of steroids (1987)
    New York, NY : Wiley-Blackwell
    Biomedical Chromatography 2 (1987), S. 189-192 
    Details
    ISSN: 0269-3879
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: We have developed a high performance thin layer chromatography (HPTLC) system for quantitative determination of androgens, corticosteroids, mineralocorticoids and gestagens on silicagel KG-60 HPTLC-plates with different solvent systems. A complete separation of androgens, gestagens and metabolites was achieved with dichlormethane/cyclohexane/acetone (70:25:5). Corticosteroids, mineralocorticoids and their derivatives were completely separated with diethylether/isooctane/isopropanol (70:25:5). The quantitative in situ fluorescence determination was carried out after post-chromatographic derivatization with cinnamic aldehyde, 4-dimethylaminobenzaldehyde and sulfuric acid. The sensitivity of detection was found between 500 pg and 1 ng per spot.The steroid metabolism as catalysed by rat liver microsomal oxidoreductases was measured by these procedures, and was compared with determination of steroids by gas chromatography (GC). According to HPTLC, steroids were reduced by NADPH-5α-reductase (EC 1.3.1.4) in the order progesterone 〉 testosterone 〉 aldosterone 〉 cortisol 〉 corticosterone. The enzyme activities as measured by HPTLC agree well with those obtained by GC (r = 0.94). When turnover of enzyme assays, speed of determination, detection limit, application to labile steroids and costs of steroid determination are considered, all points speak in favour of HPTLC.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bmc.1130020503
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...