Volume 50, Issue 2 (March 2005)

    Adsorption Saturation and Chromatographic Distortion Effects on Passive Headspace Sampling with Activated Charcoal in Fire Debris Analysis

    (Received 3 July 2004; accepted 25 September 2004)

    Published Online: March

    CODEN: JFSOAD

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    Abstract

    Distortion of the chromatographic profile obtained for hydrocarbons that have been sampled by adsorption onto activated charcoal is a well-known phenomenon. The work reported here helps to better define the causes of chromatographic profile distortion and offers a potential method to avoid chromatographic distortion in some cases through a subsampling technique. The recovery of hydrocarbons from an equimolar mixture was investigated to determine the influence of hydrocarbon concentration on the molar ratios of recovered components. In a one-quart container, hydrocarbon volumes as small as 24 μL (liquid) were sufficient to saturate the surface area available for adsorption on a 99.0 mm2 square of activated charcoal, resulting in significant distortions in the molar ratio and the chromatographic profile of the recovered hydrocarbons. Passive headspace sampling of a similarly small volume of unweathered gasoline spiked onto carpet padding resulted in a significant distortion of the chromatographic profile. The chromatographic profile of the recovered hydrocarbons closely resembled 75% weathered gasoline. Heating the container spiked with unweathered gasoline to evenly distribute the components and then removing a subsample of the carpet padding to a second container for passive headspace analysis greatly reduced the amount of distortion in the resulting chromatogram.


    Author Information:

    Bridge, C
    University of Central Florida, Orlando, FL

    Dorrien, D
    University of Central Florida, Orlando, FL

    Fernandes, D
    University of Central Florida, Orlando, FL

    Williams, MR
    University of Central Florida, Orlando, FL

    Sigman, M
    University of Central Florida, Orlando, FL

    Elliott, S
    University of Central Florida, Orlando, FL


    Stock #: JFS2004274

    ISSN: 0022-1198

    DOI: 10.1520/JFS2004274

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    Author
    Title Adsorption Saturation and Chromatographic Distortion Effects on Passive Headspace Sampling with Activated Charcoal in Fire Debris Analysis
    Symposium , 0000-00-00
    Committee E30