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
Filter
  • Analytical Chemistry and Spectroscopy  (5)
Collection
Keywords
  • Analytical Chemistry and Spectroscopy  (5)
  • Chemistry  (5)
Publisher
Years
  • 1
    Electronic Resource
    Electronic Resource
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 4 (1977), S. 275-279 
    ISSN: 1052-9306
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A new metabolite of 5,5-diphenylhydantoin has been found in human urine and in rat bile. This new metabolite arises by direct glucuronidation of 5,5-diphenylhydantoin (i.e. no prior aryl hydroxylation occurs) and is characterized as the N-3 glucuronide. This structure assignment is based on (a) study of mass spectra of permethyl, perdeuteriomethyl, N-methyl-per-O-deuteriomethyl and deuteriomethyl ester permethyl derivatives and (b) comparison of the reactions of the new glucuronide metabolite and 5,5-diphenyl-3-methylhydantoin with diazomethane. Prominent ions at m/e 322 and 378 in the mass spectrum of the permethylated derivative of the glucuronide metabolite arise via retro Diels-Alder reactions of the glycone ring.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 2
    Electronic Resource
    Electronic Resource
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 4 (1977), S. 146-151 
    ISSN: 1052-9306
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Quantitative analyses of subnanomole quantities of the polyamines putrescine, cadaverine, spermidine and spermine by the gas chromatography mass spectrometry technique of selected ion monitoring are complicated by effects of the chromatographic column. These effects include sample retention by the column and chromatographic band broadening, and are sufficiently serious that spermine (as the trifluoroacetylated derivative) was not detectable at levels below 50 picomoles. Because the chromatographic behaviors of the four polyamines vary, quantiative analysis using a single internal standard is not feasible. The deuterated polyamine analogs, putrescine-2H4, cadaverine-2H4, spermidine-2H6 and spermine-2H8, have been synthesized and used to accomplish quantiative analyses of the corresponding isotopically natural abundance polyamines to the one picomole level. This enhancement in analytical sensitivity is accomplished by use of large excesses (≥100 picomoles) of the deuterated analogs to improve chromatographic band profiles. The use of such large molar excesses of deuterated analogs for selected ion monitoring analyses is possible because their electron impact spectra exhibit high mass ions {[M-F3C]+, [M-F3CCO]+} which possess ≥ 4 deuterium atoms and have intensity ratios (I2H(max): IH) of 500 or greater.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 3
    Electronic Resource
    Electronic Resource
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 8 (1981), S. 144-148 
    ISSN: 1052-9306
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Folic acid and several analogs have been characterized as their permethylated derivatives. These derivatives are readily evaporated from the solid probe and provide spectra with abundant molecular ions and characteristic fragment ions. This method has been used to confirm the identities of the two methotrexate metabolites, 7-hydroxymethotrexate and 4-amino-4-deoxy-N10-methylpteroic acid, which have been isolated from human urine. The permethylation products of the folate cofactors, dihydrofolic acid, tetrahydrofolic acid and leucovorin, are also characterized.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 4
    ISSN: 0306-042X
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A sensitive and specific method for the quantitative determination of a new antitumor agent,l-(2-chloroethyl)-3-(2,6-dioxo-3-piperidyl)-1-nitrosourea, (PCNU) has been developed for the analysis of plasma. This assay involves extraction of the plasma sample, separation of the drug by thin-layer chromatography and mass spectrometric detection of the negative ions derived from the unchanged drug and its 2H4-labeled analog. Ion current profile peaks are obtained when drug samples are introduced into the heated source using a desorption chemical ionization probe. Detection limits are below 1.0 ng ml-1 of plasma. This method has been applied to determine the in vitro rate of decomposition of PCNU in plasma and the plasma clearance of this drug from a cancer patient.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 5
    Electronic Resource
    Electronic Resource
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 5 (1978), S. 515-517 
    ISSN: 0306-042X
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Using gas chromatography mass spectrometry following derivatization (N-trifluoroacetylation), 1-N-acetylspermidine was found to occur in normal human serum at a level of approximately 0.008-0.05 nmol ml-1, i.e. about two orders of magnitude lower than the corresponding spermidine level. No evidence for the occurrence in serum of the isomeric 8-N-acetylspermidine was found. Mass spectra of authentic samples of trifluoroactylated 1-N- and 8-N-acetylspermidine are presented.
    Additional Material: 1 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...