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  (2,408)
  • CHEMISTRY
  • unknown
Collection
Publisher
  • 1
    ISSN: 0377-0486
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The free radical cation of 1,4-diaminobenzene (p-phenylenediamine, PPD+.) has been generated in aqueous solution, wherein it is short-lived, by oxidation of the parent compound with bromine. The same PPD+. radical has also been produced by UV photolysis of the parent at 77 K in an ethanolic glassy matrix. Resonance Raman spectra of the radical and its parent are reported and analysed in detail with the aid of normal coordinate and molecular orbital calculations. Evidence is presented for (PPD+.)2 dimer formation in aqueous solution at room temperature.
    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 17 (1982), S. 481-492 
    ISSN: 0030-493X
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Doubly charged ion mass spectra were obtained for 46 low molecular weight oxygen containing compounds. A double focusing Hitachi RMU-7L mass spectrometer, operated at 3.2 kV accelerating voltage, was used to measure spectra for aliphatic alcohol, ketone, ether, aldehyde, ester and acid molecules, as well as several aromatic oxygen containing compounds. In general, the spectra were dominated by fragment ions which resulted from extensive H loss and C—C bond rupture as well as O elimination from the doubly charged molecular ions. Total product ion intensities from doubly charged ion spectra of aliphatic oxygen containing compounds were approximately 1% of the corresponding total ion intensity in the benzene doubly charged ion spectrum. Appearance energies for forming prominent doubly charged molecular and fragment ions were determined. Measured values ranged from 26 to 45 eV. A geometry optimized quantum mechanical SCF treatment was used to compute the energies, charge densities and structures for several of these oxygen containing doubly charged ions.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 3
    Publication Date: 2005-11-13
    Keywords: unknown
    Type: SURVEYOR 3 PRELIMINARY SCI. RESULTS 15 MAY 1967 (SEE N69-78676)
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 4
    Publication Date: 2013-08-31
    Description: Review of material research at Marshall Space Flight Center
    Keywords: CHEMISTRY
    Type: RES. ACHIEVEMENTS REV., VOL. 2 1968 (SEE N69-18059 07-34)
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 5
    Electronic Resource
    Electronic Resource
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 15 (1988), S. 123-128 
    ISSN: 0887-6134
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A new mass spectral method has been developed and used to identify biologically important thiols. This method is based upon the use of C-14 labeled N-para-bromophenylmaleimide (BPM) to selectively derivatize thiols. The isotopic label facilitates the isolation and purification of trace quantities of the maleimide thiol adducts by high performance liquid chromatography (HPLC) with radioactivity detection. The use of the bromine atom in the thiol derivative greatly enhances the detectability of the parent and fragment ions containing the BPM moiety because of the generation of the characteristic N + 2 doublet ions. Several examples of the use of this method to identify non-volatile thiol peptides such as glutathione (GSH) and homoglutathione (hGSH) by fast atom bombardment mass spectrometry (FAB-MS) are described in this report.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 6
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 2 (1979), S. 621-622 
    ISSN: 0935-6304
    Keywords: Uroporphyrin isomer separation ; HPLC uroporphyrin free acid ; Uroporphyrin isomers in urine ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A synthetic mixture of uroporphyrin isomers I, II, III and IV as free acids in the synthetic ratio of 1:1:4:2 was resolved by reverse-phase HPLC using a C0:PEL (ODS) 37-50 micron precolumn and a Micro Bondapak C18 analytical column eluted with acetonitrile (4%) in phosphate buffer (pH 6.95). Clinically important I and III isomers of uroporphyrin were readily resolved directly from acidified urine as porphyrin free acids.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 7
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 6 (1983), S. 300-305 
    ISSN: 0935-6304
    Keywords: Fused silica capillary columns ; Flexibility ; Polyimide coating ; Cobalt-60 gamma radiation ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Five commercial varieties of uncoated fused silica capillary tubing used in high resolution gas chromatography were subjected to cobalt-60 gamma radiation. The advantages and superior performance of fused silica open tubular columns coated with OV-1 and subsequently immobilized or crosslinked in situ by radiation is reported in a previous paper in this Journal; however, in this investigation a loss in flexibility of irradiated capillaries was also noted. Quantitative measurements on flexibility were performed on specimens of irradiated fused silica capillaries, indicating that changes do indeed occur upon irradiation. Scanning electron micrographs also illustrate slight deterioration of the outer protective polyimide coating. Most surprisingly, it was also established that a variation does exist in the flexibility of the commercially available raw material studied.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 8
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 11 (1988), S. 29-32 
    ISSN: 0935-6304
    Keywords: Capillary supercritical fluid chromatography ; Injection techniques ; Reproducibility ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: An analysis of the precision obtained using commercially available microvalve injectors is reported for three modes of injection: conventional split; timed-split; and direct. Results from this study show that good precision (〈 3% RSD for external standard and 〈 1% RSD for internal standard methods) can be obtained with capillary supercritical fluid chromatography (SFC). However, particular attention must be paid to the type of valve used, the orientation of the column relative to the valve, the mode of interfacing or connecting the column to the valve, and the type of pressure or density programming used for the analysis as all of these factors will affect the reproducibility.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 9
    Electronic Resource
    Electronic Resource
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 3 (1976), S. 196-200 
    ISSN: 1052-9306
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Organic vapors in ambient air, at or near an industrial site in Baltimore, Maryland, were collected by adsorption on a sorbent of porous polymer (Tenax GC, 35/60). The pollutants were recovered by thermal desorption and analyzed by gas-liquid chromatography mass spectrometry computer using capillary glass SCOT columns. N-Nitrosodimethylamine was identified from its mass spectrum as a constituent of the atmosphere in the areas sampled. The identification of this compound was confirmed by comparison of its mass spectrum with that of authentic N-nitrosodimethylamine; identical retention times of unknown and authentic compound on three different capillary columns were observed.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 10
    ISSN: 1052-9306
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A new approach is presented to overcome the problems imposed by the use of non-volatile mobile phase constituents, such as buffers, in liquid chromatographic/mass spectrometric applications. The approach, called phase-system switching (PSS), is based on the use of valve switching techniques. The peak of interest is heart-cut from the effluent of the analytical column and trapped on a short trapping column, the buffer constituents are washed off, and subsequently the compound of interest is desorbed in a solvent favourable for the liquid chromatograph/mass spectrometer interface. The potential of the phase-system switching technique is explored in the liquid chromatographic/mass spectrometric analysis of the anti-cancer drug mitomycin C, which is chromatographed with an aqueous phosphate buffer as the mobile phase on a reversed-phase column. In addition to the phase-system switching itself, the PSS technique shows the interesting possibilities of peak compression and changes in flow rate.
    Additional Material: 4 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...