ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

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
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 13 (1990), S. 737-741 
    ISSN: 0935-6304
    Keywords: Packed capillary liquid chromatography ; Hop bitter acids ; Beer bitter acids ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: High efficiency liquid chromatography (LC) on both coupled conventional columns and long micro-LC columns, both with diode array detection, has revealed the presence of some hitherto unknown compounds in hop extracts. Proof is advanced that ethanol extracts of hops contain iso-alpha acids.The elution order of the cis-trans pairs of the iso-alpha acids, and the separation of the alpha acids from the deoxyalpha acids, is reversed by switching from methanol to acetonitrile in the reversed phase solvent system.An LC solvent system giving higher resolution (higher selectivity factor) of the iso-alpha acid cis and trans stereoisomers is obtained by adding magnesium salts to the eluent.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 2
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 13 (1990), S. 295-298 
    ISSN: 0935-6304
    Keywords: Capillary zone electrophoresis, CZE ; Micellar electrokinetic chromatography, MEKC ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 3
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 13 (1990), S. 826-831 
    ISSN: 0935-6304
    Keywords: Liquid chromatography ; Beer ; Iso-alpha acids ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: This paper shows that the liquid chromatography (LC) methods so far described in the literature for iso-alpha acids analysis are unsatisfactory. The main reasons for this are the failure of the advocated eluent systems to completely suppress trace metal activity of commercial LC columns and the lack of a stable reference iso-alpha acid.The trace metal problem can be solved by using a column packing material specifically designed for “Hop Acid” analysis and by adding ethylenediaminetetraacetate (EDTA) to the eluent. The reference problem is more difficult, but possibly a formulation of the iso-alpha acids in their acid form may be the answer.Chromatographic conditions changing the elution pattern of the individual iso-alpha acids are studied. This leads to better control of their co-elution in the analytical procedure.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 4
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 14 (1991), S. 584-586 
    ISSN: 0935-6304
    Keywords: Micellar electrokinetic chromatography ; Identification by multi-wavelength detection ; Food analysis ; Beer iso-α-acids ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The identification of beer bitter acids in a pre-isomerized hop extract by means of their UV-spectra is described. Preliminary data for the analysis of these compounds in beer samples are presented.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 5
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 31 (1988), S. 418-425 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: A novel two-stage anaerobic process for the microbial conversion of cellulose into biogas has been developed. In the first phase, a mixed population of rumen bacteria and ciliates was used in the hydrolysis and fermentation of cellulose. The volatile fatty acids (VFA) produced in this acidogenic reactor were subsequently converted into biogas in a UASB-type methanogenic reactor.A stepwise increase of the loading rate from 11.9 to 25.8 g volatile solids/L reactor volume/day (g VS/L/day) did not affect the degradation efficiency in the acidogenic reactor, whereas the methanogenic reactor appeared to be overloaded at the highest loading rate. Cellulose digestion was almost complete at all loading rates applied. The two-stage anaerobic process was also tested with a closed fluid circuit. In this instance total methane production was 0.438 L CH4g VS added, which is equivalent to 98% of the theoretical value. The application of rumen microorganisms in combination with a high-rate methane reactor is proposed as a means of efficient anaerobic degradation of cellulosic residues to methane. Because this newly developed two-phase system is based on processes and microorganisms from the ruminant, it will be referred to as “Rumen Derived Anaerobic Digestion” (RUDAD-) process.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...