Library

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
    Springer
    Chromatographia 30 (1990), S. 159-162 
    ISSN: 1612-1112
    Keywords: Column liquid chromatography ; Amino acids analysis ; Peptide hydrolysis ; Microwave accelerated hydrolysis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary An improved method for the quantitative determination of amino acids using HPLC, after preliminary derivatisation with o-phthalaldehyde, is described. Separation was carried out on a LiChrospher RP-18 column, using gradient elution and a fluorescence detector. Hydrolysis was performed with 6M HCl or with 3M p-toluenesulphonic acid depending on the amount of carbohydrates in the sample. In addition, the time required for total hydrolysis was shortened from 24 hours to 15 minutes by the use of a microwave oven. The results with these two hydrolytic methods are compared with regard to the extent of peptide bond cleavage and the percentage of decomposition of amino acids in a test mixture.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 2
    Electronic Resource
    Electronic Resource
    Springer
    Fresenius' Zeitschrift für analytische Chemie 341 (1991), S. 720-722 
    ISSN: 1618-2650
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary A simple and rapid head space gas-chromatographic method for the determination of residual ethylene oxide in surfactants used in shampoos and other cosmetic products is described. The analyte was determined in various materials in the concentration range between 0.1 and 10 μg/g and sufficient linearity of response was observed to allow use of the calibration line and/or the standard addition method (r≥0.977). In comparison with extraction and adsorption procedures for sampling of ethylene oxide prior to analysis, the head space technique is faster and more accurate but suffers in precision. Coefficients of variation by the interpolation of the calibration line of 10% to 30% are typical for standard solutions in methylene chloride and real samples. Better precision was obtained by the standard addition method.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 3
    Electronic Resource
    Electronic Resource
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 28 (1993), S. 1570-1576 
    ISSN: 0030-493X
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Mass spectra of the saturated vapour and partial pressures of different species over solid InI3 were measured between 350 and 450 K with a mass spectrometric Knudsen effusion technique. By measuring appearance energies (AE) for different ions in the mass spectra, it was proved that InI3 evaporates congruently from the solid phase as InI3(g) and In2I6(g). Values of AE for In2In+ ions (n = 0-5) increase as n decreases, showing an interesting periodicity with In—I bond strengths. For these measurements an improved deconvolution of the ionization efficiency curves by fast Fourier transformation, using a combined Maxwellian and Gaussian electron energy distribution, was performed. By measuring ion abundances as a function of temperature, the Clausius-Clapeyron plots for all ions appearing in the mass spectra were drawn.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...