1. Skip to navigation
  2. Skip to content
  3. Skip to secondary content
  4. Skip to sidebar



MESL Facilities Organic Laboratories

MESL is equipped with 5 laboratories for organic analysis. Separate laboratories are used for sample preparation and instrumental analysis.




    Organic contaminants analysis

    Many organic contaminants in marine samples are analysed at MESL. The list includes:

    • Petroleum hydrocarbons
      • total petroleum hydrocarbons (TPH)
      • individual aliphatic hydrocarbons
      • individual polycyclic aromatic hydrocarbons (PAHs)
    • Chlorinated pesticides
      • DDT and its breakdown products (DDE and DDD)
      • other pesticides banned by the Stockholm Convention
    • Organohalogen compounds
      • polychlorinated biphenyls (PCBs)
      • polybrominated diphenyl ethers (PBDEs)
    • Other organic compounds, such as organophosphorus pesticides, antifouling compounds and faecal sterols.
    Chromatograms of polychlorinated biphenys (PCBs)
    Chromatograms of hydrocarbons


    Sample Preparation for organics contaminants

    Microwave extraction system

    Sediment and biota samples are solvent extracted using a microwave extraction system (CEM MARSX). Isolation of organic contaminants is performed on column chromatography, such as silica-gel, alumina and Florisil. The isolated compound classes are analysed by Gas Chromatography.

    Column chromatography



    Lipid biomarkers analysis

    Chromatograms of lipid
    biomarkers

    The list of lipid biomarkers analysed at MESL includes:

    • aliphatic and aromatic hydrocarbons
    • ketones, e.g., long-chain alkenones
    • sterol and fatty alcohol compounds
    • fatty acids.






    Sample Preparation for lipid biomarkers

    HPLC used for sample preparation
    of lipid biomarkers

    Samples are solvent extracted using a microwave extraction system (CEM MARSX) or alternatively sonicated and shaked. Neutral and acidic lipid biomarkers are isolated by solvent extraction of the saponified extract and normal-phase HPLC is used to separate the different classes of neutral compounds. Final determination is accomplished by Gas Chromatography

    SPE column chromatography used for
    samplepreparation of lipid
    biomarkers







    References:
    • Isolation of neutral and acidic lipid biomarker classes for compound-specific-carbon isotope analysis by means of solvent extraction and normal-phase high-performance liquid chromatography. J. Chromatogaphy. A, 1045, 71-84, (2004).



        Equipments



        Gas Chromatography (GC)

        Gas chromatography room

        The organic sample extracts are analyzed by gas chromatography. MESL is equipped with several GCs.

        The GCs are set up for particular analyses, optimised with respect to the column used and the detector type. The various detectors include:

        • Flame Ionisation Detector (FID) for hydrocarbons, sterols and fatty acids.
        • Electron Capture Detector (ECD) for halogenated compounds
        • Nitrogen - Phosphorus Detector (NPD) for nitrogen and phosphorus compounds
        • Flame Photometric Detector (FPD) for organotins


        Gas Chromatography - Mass Spectrometry (GC-MS)

        Gas chromatography-mass
        spectrometer (GC-MS)

        A Mass Spectrometer as detector for a Gas Chromatograph produces a powerful analytical tool with multiple applications. The instrument can be used for the analysis of complex mixtures of compounds with similar properties, notably PAHs and PBDEs. Also, the GC-MS enables compound verification / validation of measurements made by other GC procedures.



        Gas Chromatography - Combustion - Isotope Ratio Mass Spectrometry (GC-C-IRMS)

        GC-C-IRMS instrument to measure
        carbon isotope ratios in individual
        organic compounds

        MESL has access to Gas Chromatography-Combustion-Isotope Ratio Mass Spectrometry (GC-C-IRMS). This instrument is used to measure the d 13C in individual organic components. Potential applications include:

        • source apportionment assessments
        • investigations of carbon cycling and behaviour
        • reconstructing the environmental and climatic conditions from the sedimentary record as an indicator of global change