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  • 1990-1994  (1)
  • 1975-1979  (5)
  • 1970-1974  (5)
  • Chemistry  (10)
  • alginate
  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Journal of applied phycology 2 (1990), S. 223-230 
    ISSN: 1573-5176
    Keywords: Chlorella ; immobilization ; mercury ; accumulation ; volatilization ; alginate
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The accumulation and volatilization of mercury by non-immobilized and immobilizedChlorella emersonii have been studied in batch culture systems. Reduction in the mercury concentration in the growth medium by non-immobilized cells was highly dependent on inoculum density, whilst reduction in mercury concentration by immobilized cells was rapid at all inoculum densities. Mercury accumulation by immobilized cell biomass was significantly greater than by non-immobilized cells with 106 and 105 cells bead−1 or ml−1. Volatilization of mercury by non-immobilized cell systems was greatest at higher inoculum densities, whereas more mercury was volatilized from immobilized cell systems at lower inoculum densities, and was greatest with unstocked alginate beads. Thus, in immobilized systems, mercury removal from solution is complex and involves mercury accumulation by the cells and volatilization by the matrix and cells. Further studies of mercury accumulation and volatilization by unstocked immobilization matrices revealed that agarose volatilized much less mercury than alginate or agar. The precise mechanism of mercury volatilization by alginate remains unclear, though it is thought to be a chemical effect.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 16 (1974), S. 1103-1112 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: β-Galactosidase has been purified from an ammonium sulfate precipitate of E. coli strain ML308 by biospecific adsorption on a column of agarose gel substituted with p-aminophenyl-β-D-thiogalactopyranoside. The system described using a 1.8 liter column has a useful processing capacity of 3.8 × 106 units of β-galactosidase per 2 hr cycle. This corresponds to about 5 g of pure enzyme. An electromechanical timing device operates a set of six solenoid valves and carries out a preset program consisting of sample application, washing, and elation operations.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 15 (1973), S. 603-606 
    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
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  • 4
    ISSN: 1052-9306
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Phenacetin, paracetamol and acetanilide can be determined in a plasma or urine sample by the use of deuterium labelled analogues. These are produced by reaction of hexadeuterioacetic anhydride with the appropriate aromatic amine. The -NHCOCD3 group is stable to hydrogen exchange below pH 8. The internal standard is added to the plasma or urine after enzymatic hydrolysis of the paracetamol conjugates and an ethyl acetate extract at pH 5 is evaporated under nitrogen and the residue derivatized with N, O-bis-(trimethylsilyl)-acetamide. An aliquot of this solution is injected into a g.c.m.s. system, and one ion characteristic of the material under study and the ion from the deuterium analogue (3 mass units greater) are monitored using a voltage switching technique. In the case of phenacetin, for example, ions at 251 and 254 are monitored. Calibration curves relating different weight ratios of the hydrogen and deuterium compounds to their respective signals from the gas chromatograph mass spectrometer are used to calculate the amount of a compound in a particular sample. These methods have been developed to study the oxidation of acetanilide to paracetamol and the de-ethylation of phenacetin to paracetamol. Preliminary results from experiments with phenacetin will be discussed.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
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  • 5
    Electronic Resource
    Electronic Resource
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 2 (1975), S. 304-306 
    ISSN: 1052-9306
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The identification of 6-methoxy 8-aminoquinoline as a metabolite of Primaquine, an important antimalarial drug, is described. The metabolite is present in urine, plasma and erythrocytes following drug ingestion. It was identified by mass fragmentography of its 1H and 2H acetate and the acetate produced from authentic material. No evidence of further metabolites was obtained.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
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  • 6
    ISSN: 1052-9306
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A method has been developed for single ion monitoring of diphenylhydantoin and its major metabolite 5-(p-hydroxyphenyl)-5-phenylhydantoin in plasma. A plasma extract is reacted with N, O-bis(trimethylsilyl)acetamide and single ion recording is carried out using a gas chromatograph mass spectrometer system. The mass value selected, m/e 254, is common to the TMS ethers of diphenylhydantoin and its principal metabolite 5-(p-hydroxyphenyl)-5-phenylhydantoin. The results indicate that one cause of an adverse reaction to diphenylhydantoin could be a reduced ability to hydroxylate the drug. Quantitative methods for the analysis of the drug and its major metabolite have also been developed. Diphenylhydantoin and 5-(p-hydroxyphenyl)-5-phenylhydantoin can be analysed in plasma after addition of deuterium labelled internal standards and conversion to volatile derivatives for mass fragmentographic analysis. Diphenylhydantoin and its internal standard are analysed as the N, N-dimethyl derivative, and the hydroxylated metabolite and its internal standard are converted to a pertrimetylsilyl compound by reaction with N, O-bis-(trimethylsilyl)acetamide.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
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  • 7
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 5 (1973), S. 137-147 
    ISSN: 0538-8066
    Keywords: Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Cyclopropyl cyanide isomerizes in the gas phase at 660°-760°K and 2-89 torr to give mainly cis- and trans-crotonitrile and allyl cyanide, with traces of methacrylonitrile. The reactions are first order, homogeneous, and unaffected by the presence of radical-chain inhibitors. The rate constants are given by Overall: \documentclass{article}\pagestyle{empty}\begin{document}$$\log _{10} k/{\rm sec}^{ - 1} = (14.58 \pm 0.08) - (242.0 \pm 1.2){\rm kJ}\,{\rm mole}^{ - 1} /2.303RT$$\end{document} cis-Crotonitrile: \documentclass{article}\pagestyle{empty}\begin{document}$$\log _{10} k/{\rm sec}^{ - 1} = (14.01 \pm 0.11) - (237.6 \pm 1.4){\rm kJ}\,{\rm mole}^{ - 1} /2.303RT$$\end{document} trans-Crotonitrile: \documentclass{article}\pagestyle{empty}\begin{document}$$\log _{10} k/{\rm sec}^{ - 1} = (14.09 \pm 0.07) - (243.7 \pm 0.9){\rm kJ}\,{\rm mole}^{ - 1} /2.303RT$$\end{document} Allyl cyanide: \documentclass{article}\pagestyle{empty}\begin{document}$$\log _{10} k/{\rm sec}^{ - 1} = (14.59 \pm 0.13) - (252.0 \pm 1.8){\rm kJ}\,{\rm mole}^{ - 1} /2.303RT$$\end{document} where the error limits are standard deviations. On the basis of a biradical mechanism, it is deduced that the —CH—CN radical center is resonance stabilized by ca. 30 kJ mole-1. Approximate equilibrium data are given for interconversion of the 1- and 3-cyanopropenes.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
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  • 8
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 5 (1973), S. 329-331 
    ISSN: 0538-8066
    Keywords: Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The high-pressure isotopic rate ratio kH/kD for isomerisation of cyclopropylamine and cyclopropylamine-N-d2 is 1.06 at 649-678 K, supporting a mechanism which does not involve migration of hydrogen from the amine group in the rate-determining step.
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
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  • 9
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 9 (1977), S. 503-505 
    ISSN: 0538-8066
    Keywords: Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 2 Tab.
    Type of Medium: Electronic Resource
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  • 10
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 5 (1973), S. 27-35 
    ISSN: 0538-8066
    Keywords: Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: At temperatures of 356-425°C and pressures of 15-60 Torr, cyclopropylamine reacts to give an equimolar mixture of ammonia and N-propylidenecyclopropylamine as the initial product. The reaction is first order, homogeneous, and unaffected by the presence of radical inhibitors, and thus proceeds by an initial rate-determining unimolecular isomerization to give a reactive intermediate, which then reacts with a further molecule of cyclopropylamine to give the observed products. Reaction in the presence of added aliphatic amines gives other imines in addition, and the nature of these indicates that the intermediate is propenylamine or its tautomer propylideneamine:
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
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