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  • 1
    Electronic Resource
    Electronic Resource
    Über die Ursachen der Reaktion zwischen trockenem Atemkalk und halogenierten Inhalationsanästhetika (1997)
    Springer
    Der Anaesthesist 46 (1997), S. 1054-1063 
    Details
    ISSN: 1432-055X
    Keywords: Schlüsselwörter Inhalationsanästhetika ; Sevofluran ; Isofluran ; trockener Atemkalk ; Zerfallprodukte ; Natriumhydroxid ; Kaliumhydroxid ; Toxizität ; Wärmeentwicklung ; Key words Inhalation anaesthestics ; Sevoflurane ; Isoflurane ; Dry soda lime ; Degradation products ; Sodium hydroxide ; Potassium hydroxide ; Toxicity ; Heat production
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Abstract All volatile anesthetics undergo chemical breakdown to multiple, partly identified degradation products in the presence of dry soda lime. These chemical reactions are highly exothermic, ranging from 100° C for halothane to 120° C for sevoflurane. The increase in temperature correlates with the moisture content of the soda lime, being maximal below 5%. Sevoflurane and isoflurane were exposed to dry soda lime in a circle system. The anaesthetic gas was condensed in a series of cold temperature traps and the degradation products of the volatile anesthetics were analysed using GC/MS. Surprisingly, neither sevoflurane nor its degradation products could be measured in the gas-flow emerging from the soda lime during the first 15–20 min of exposure. After 20 minutes, larger quantities of methanol, compounds C and D as well as compounds A and B were detected. After 40–60 min of exposure, sevoflurane’s degradation markedly decreased and unaltered sevoflurane emerged from the soda lime canister. Additionally, using isoflurane in the same experimental set-up resulted in various degradation products due to its reaction with dry soda lime. Obviously, all volatile anesthetics are prone to such a reaction. In conclusion, sevoflurane and isoflurane react with dry soda lime. These reactions are caused by the presence of two components of soda lime, sodium hydroxide and potassium hydroxide. A modification of soda lime to prevent its reaction with volatile anaesthetics is discussed.
    Notes: Zusammenfassung Alle halogenierten Inhalationsanästhetika unterliegen in Anwesenheit von trockenem Atemkalk einem chemischen Zerfall zu zahlreichen, zum Teil noch nicht bekannten und nicht identifizierten Produkten. Bei den Reaktionen entwickeln sich sehr hohe Temperaturen, die beim Halothan Werte von 100° C, beim Sevofluran 120° C erreichen können. Die Heftigkeit der Reaktion ist vom Feuchtegrad des Atemkalks abhängig und findet ihr Maximum unterhalb eines Wassergehalts von 5%. An einem Narkosegerät wurde die Reaktionen von Sevofluran und Isofluran mit trockenem Atemkalk simuliert, das Narkosegas anschließend in einer Kühlfalle kondensiert und die Reaktionsprodukte mittels GC/MS gemessen. Bei großer Hitzeentwicklung zerfällt Sevofluran unter diesen Bedingungen zu zahlreichen Reaktionsprodukten. Überraschend war der Nachweis, daß während der ersten 15–20 min nach „Narkosebeginn” weder Sevofluran noch Reaktionsprodukte den Atemkalk verließen. Später wurden erstmals in einem Narkosesystem größere Mengen von Methanol sowie Compound C und D neben großen Mengen von Compound A und B gemessen. Durch kontinuierliche Messungen kann der zeitliche Verlauf der Reaktion von Sevofluran mit Atemkalk verfolgt werden. Die Reaktion klingt nach 40–60 min ab. Erst dann werden ausreichende Sevoflurankonzentrationen erreicht. Der zu diesem Zeitpunkt eine Sättigung des Atemkalks anzeigende Farbumschlag konnte auf eine chemische Veränderung des Indikators zurückgeführt werden. Auch bei Einsatz von Isofluran konnte bei einer Reaktion mit trockenem Atemkalk das Entstehen mehrerer Reaktionsprodukte exemplarisch festgestellt werden. Es wird gefolgert, daß alle halogenierten Gasanästhetika mit trockenem Atemkalk reagieren können. Diese Reaktion ist auf den Gehalt des Atemkalks an Kaliumhydroxid und an Natriumhydroxid zurückzuführen. Die Möglichkeit, durch eine Veränderung des Atemkalks die Reaktion zu verhindern, wird erörtert.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s001010050506
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  • 2
    Electronic Resource
    Electronic Resource
    Unterschiedliche Reaktion von Sevofluran mit einzelnen Komponenten von Atemkalk (1997)
    Springer
    Der Anaesthesist 46 (1997), S. 1071-1075 
    Details
    ISSN: 1432-055X
    Keywords: Schlüsselwörter Sevofluran ; Sevofluranreaktionen ; Kaliumhydroxid ; Natriumhydroxid ; Kalziumhydroxid ; Bariumhydroxid ; Key words Sevoflurane ; Sevoflurane reactions ; Potassium hydroxide ; Sodium hydroxide ; Calcium hydroxide ; Barium hydroxide
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Abstract The various components of commercial soda lime (sodium hydroxide, potassium hydroxide, calcium hydroxide, barium hydroxide) were studied in terms of their reactivity with sevoflurane at its boiling point (59° C). A simple closed system, a reflux cooler, served as a model. Analyses were performed by GC/MS. Besides sevoflurane, we identified four compounds: A, B, C, and D. Free methanol, formaldehyde and formic acid could not be found. Presumably methanol is transferred from an intermediate formalin-semiacetal of the hexafluorisopropanol. Calcium hydroxide and barium hydroxide showed little reaction with sevoflurane, whereas larger amounts of reaction products were observed with sodium hydroxide and potassium hydroxide. The alkali hydroxides of sodalime are presumably responsible for its reaction with halogenated inhalation anaesthetics. We therefore conclude that decomposing reactions of halogenated inhalation anesthetics with dry soda lime could be prevented by using a newly developed soda lime.
    Notes: Zusammenfassung In einem einfachen geschlossenen System als Modell (Rückflußkühler) wurden die verschiedenen Komponenten von kommerziellem Atemkalk (Natriumhydroxid, Kaliumhydroxid, Kalziumhydroxid, Bariumhydroxid) auf ihr Reaktionsverhalten mit Sevofluran an dessen Siedepunkt (59° C) untersucht. Die Analysen erfolgten mittels GC/MS. Identifiziert wurden neben Sevofluran Compound A, B, C, D. Freies Methanol wurde ebenso wie Formaldehyd oder Ameisensäure nicht gefunden. Daher wird angenommen, daß eine Methanolübertragung aus einem intermediären Formaldehydsemiacetal mit Hexafluorisopropanol erfolgt. Während Kalziumhydroxid und Bariumhydroxid kaum eine Reaktion mit Sevofluran zeigen, können mit Natriumhydroxid und Kaliumhydroxid die entsprechenden Reaktionsprodukte in größerem Umfang festgestellt werden. Es wird daher gefolgert, daß die Alkalihydroxide des Atemkalks für dessen Reaktion mit halogenierten Inhalationsanästhetika verantwortlich sind. Daraus ist zu folgern, daß mittels eines neu zu konzipierenden Atemkalks die Zerfallsreaktionen von halogenierten Inhalationsanästhetika an trockenem Atemkalk verhindert werden könnten.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s001010050508
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  • 3
    Electronic Resource
    Electronic Resource
    Polypeptide sequencing by a gas chromatograph mass spectrometer computer system: II - characterization of complex mixtures of oligopeptides as trimethylsilylated polyamino alcoholsA1, A2,… ions corresponding to the N-terminal amino acid, dipeptide… in the peptide derivatives used (polyamino alcohol-OTMS-ethers). Z1, Z2 … ions corresponding to the C-terminal amino acid, dipeptide … in the peptide derivatives used. R … sidechain of amino acids (as derivatized). Δ, contribution of amino acids to the retention index value of a derivatized peptide molecule. (1975)
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 2 (1975), S. 326-339 
    Details
    ISSN: 1052-9306
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Complex mixtures of O-trimethylsilylated polyamino alcohols, which have been generated by either acid or enzymatic hydrolysis of polypeptides and subsequent derivatization, are completely characterized by a gas chromatograph mass spectrometer computer system. These peptide derivatives possess excellent gas chromatographic properties; a wide range of derivatives from di- to hexapeptides may be separated in a single chromatographic experiment. The identification of these compounds, either manually or with the assistance of the computer, is based on three sets of data which are automatically generated after the g.c.m.s. computer experiment: (1) mass spectra, which exhibit sequence-determining ions of high abundance; (2) selected ion records, which allow efficient location of peptide derivatives in the gas chromatogram as well as resolution of incompletely separated fractions; (3) retention indices, which can be calculated from values which have been assigned to each amino acid residue.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bms.1200020608
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  • 4
    Electronic Resource
    Electronic Resource
    Quantitation of clenbuteral in biological fluids using ammonia CI and automated capillary GCMS (1988)
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 17 (1988), S. 417-420 
    Details
    ISSN: 1052-9306
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bms.1200170513
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  • 5
    Electronic Resource
    Electronic Resource
    Polypeptide sequencing by a gas chromatograph mass spectrometer computer system: I - generation and derivatization of complex mixtures of oligopeptidesDAP I and DAP IV = dipeptidylaminopeptidases I and IV. (1975)
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 2 (1975), S. 313-325 
    Details
    ISSN: 1052-9306
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A generally applicable strategy for polypeptide sequencing has been developed which involves cleavage of a large peptide (for example, primary degradation peptides obtained by tryptic or cyanogen bromide cleavage of a protein) to a mixture of small peptides whose individual amino acid sequences are then determined without their prior isolation. This is accomplished by conversion of the peptide mixture into the corresponding mixture of O-trimethylsilylated polyamino alcohols through reduction of the N-acetylated peptide esters with lithium aluminum deuteride, followed by treatment with trimethylsilyldiethylamine. The conditions for the enzymatic or chemical cleavage were optimized to yield mixtures of peptides best suited for this technique and which represented complete overlap. Limited acid hydrolysis combined with a second experimen utilizing either an enzyme with broad specificity, a set of enzymes, or dipeptidyl aminopeptidase I on the original and/or Edman-degraded molecule was found to be the best choice. This sequencing strategy was evaluated using 0.4 to 1.4 μmol of peptides with known structures (ribonuclease S-peptide, glucagon) and then applied to primary degradation peptides of rabbit skeletal muscle actin up to twenty amino acids long (0.4 to 1 μmol per experiment).
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bms.1200020607
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  • 6
    Electronic Resource
    Electronic Resource
    Untersuchungen zur Azophenin-Synthese aus o-Benzochinondioxim (1986)
    New York, NY : Wiley-Blackwell
    Journal für Praktische Chemie/Chemiker-Zeitung 328 (1986), S. 921-928 
    Details
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Studies on the Synthesis of Azophenines from o-Benzoquinone Dioxime
    Additional Material: 3 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/prac.19863280536
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  • 7
    Electronic Resource
    Electronic Resource
    Darstellung, Struktur und Schwingungsspektren der Oxofluorowolframate(VI) Cs2[WO3F2] und Cs3[W2O4F7] (1982)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 494 (1982), S. 109-114 
    Details
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Synthesis, Structure, and Vibrational Spectra of the Oxofluorotungstates(VI) Cs2[WO3F2] and Cs3[W2O4F7]Cs2[WO3F2] crystallizes from a melt with the same composition. The orthorhombic unit cell with a = 6.779(2), b = 7.668(1) and c = 11.626(3) Å, space group Pn21a, contains 4 formula units. The WO3F22- anion is polymer, W octahedrally coordinated according to the results of the X-ray crystal structure determination.Planar dioxodifluoro groups are linked into chains by oxygen atoms. The lengths of the W—O bonds are alternating. Cs3[W2O4F7] crystallizes trigonal, space group P3m1, with a = 21.118(4) and c = 8.434(2) Å, Z = 9. The structure consists of two sets of crystallographically non equivalent dimeric anions with the formula [O2F3W—F—WO2F3]3-. Part of the ligand atoms are disordered. The vibrational spectra of both compounds show the presence of cis-dioxo groups of the terminal ligands.
    Notes: Cs2[WO3F2] kristallisiert aus einer Schmelze gleicher Zusammensetzung. Die orthorhombische Elementarzelle mit a = 6,779(2), b = 7,668(1) und c = 11,626(3) Å, Raumgruppe Pn21a, enthält 4 Formeleinheiten. Das Anion ist polymer, Wolfram oktaedrisch koordiniert. Planare dioxo-difluoro-Gruppen sind über transständige Sauerstoffatome zu Ketten verknüpft. Die W—O-Bindungsabstände sind alternierend kurz und lang. Cs3[W2O4F7] kristallisiert trigonal, Raumgruppe P3m1, mit a = 21,118(4) und c = 8,434(2) Å, Z = 9. Die Struktur enthält 2 kristallographisch nicht äquivalente dimere Komplexionen der Formel [O2F3W—F—WO2F3]3-. Ein Teil der Liganden ist fehlgeordnet. Die Spektren beider Verbindungen zeigen an, daß die terminalen Sauerstoffatome in cis-Stellung zueinander stehen.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/zaac.19824940114
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  • 8
    Electronic Resource
    Electronic Resource
    Über die synthese und das redoxverhalten von molekulareinheitlichen hydrochinon-phenol-formaldehydkondensaten (1962)
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 52 (1962), S. 147-163 
    Details
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: Compounds of low and uniform molecular weight were prepared by condensation of hydrochinone, phenol and formaldehyde. They were used as models for redox resins. The redox properties of these compounds were investigated by potentiometric titration. The titration curves were analyzed theoretically.
    Notes: Mit dem Ziel, Modellsubstanzen für Redoxharze, aufgebaut aus Hydrochinon, Phenol und Formaldehyd, zu erhalten, wurden niedermolekulare molekulareinheitliche Kondensate dieser Stoffe dargestellt. Das Redoxverhalten der Verbindungen wurde durch potentiometrische Titration untersucht. Der Verlauf der Titrationskurven wurde theoretisch gedeutet.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/macp.1962.020520113
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  • 9
    Electronic Resource
    Electronic Resource
    The on column methylation of clonidine and p-hydroxyclonidine with trimethylanilinium hydroxideAbbreviation: TMAOH = trimethylanilinium hydroxide. (1978)
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 5 (1978), S. 483-487 
    Details
    ISSN: 0306-042X
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The structures of the methylated clonidine derivatives formed by on column methylation with trimethylanilinium hydroxide are revised. The almost exclusive formation of derivatives of phenylimino-N,N-dimethylimidazolidine structure is explained in terms of a fast kinetically controlled reaction of substrate anions. The reliability of a stable isotope dilution assay for clonidine is discussed in view of these results.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bms.1200050804
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