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  • 1
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 15 (1992), S. 437-443 
    ISSN: 0935-6304
    Keywords: Coupled LC-GC ; Polycyclic aromatic hydrocarbons ; Automation ; Clean-up and analysis ; Lubricating oil ; Urban air ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A fully automated system, comprising a liquid chromatograph (LC) coupled on-line to a gas chromatograph (GC) by means of a loop interface, has been constructed for clean-up and analysis of polycyclic aromatic hydrocarbons (PAH). An autosampler was utilized for sample injection into the LC. By the use of a back-flush technique in conjunction with an ordinary analytical aminopropylsilica column, PAH could be isolated by LC: a concurrent solvent evaporation injection technique was then used for on-line transfer of the PAH fraction to the GC, where the PAH analysis was completed.Compared with ordinary off-line LC clean-up followed by GC analysis, the sensitivity has been increased by a factor of 50-100, yielding a detection limit for individual PAH of a few nanograms per sample when using flame ionization detection. Further, irreproducible losses of low molecular weight PAH as a result of solvent evaporation steps in off-line clean-up procedures have been eliminated. Reproducibility of retention times and relative peak areas is high, facilitating automatic peak identification and calculation of concentrations, and the system can thus be used for automatic sample evaluation. The total time required for clean-up and analysis is only 1.5 hours, and the demand on personnel time for the analysis of PAH has been drastically reduced.The technique has been demonstrated with samples of urban air and of used automobile engine lubricating oil.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
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  • 2
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 15 (1992), S. 745-750 
    ISSN: 0935-6304
    Keywords: On-line coupling ; LC-GC ; LC-GC-MS ; Liquid chromatography ; Gas chromatography ; Mass spectrometry ; Chlorinated polycyclic aromatic hydrocarbons ; Urban air ; Occupational exposure measurement ; Bus drivers ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Coupled liquid chromatography - gas chromatography - mass spectrometry (LC-GC-MS) has been applied for on-line clean up, separation, and identification of chlorinated polycyclic aromatic hydrocarbons (CI-PAHs). A loop-type interface was used to couple the liquid chromatograph on-line with the GC-MS, and concurrent solvent evaporation was used for sample transfer.A back-flush technique was used in conjunction with a two-dimensional column system for isolation of CI-PAHs and polycyclic aromatic hydrocarbons (PAHs). This fraction was transferred on-line to the GC and separated on a capillary column. Selective and sensitive detection of CI-PAHs in the GC eluate was obtained by negative ion chemical ionization (NICI) mass spectrometry and selected ion monitoring (SIM).The combined on-line system for isolation, separation, and identification showed high precision and accuracy, and demonstrated a linear response from 1 to 1000 pg for chlorinated PAHs. The estimated detection limit was 250 fg for 1-chloropyrene and 1,6-dichloropyrene.The technique was demonstrated by analysis of urban air samples. The low detection limit made it possible to use the technique for analysis of personally carried monitoring equipment for measurement of exposure to CI-PAHs in the work environment.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
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