Organic compounds in non-saline sediments 135
Gas chromatography-mass spectrometry
Tan et al [71] devised a rapid simple sample preparation technique for analysis
polycyclicaromatic hydrocarbons in sediments. Polycyclicaromatic hydrocarbons are
removed from sediment by ultrasound extraction and isolated by solvent partition
and silica gel column chromatography. The sulphur removal step is combined into
the ultrasonic extraction procedure. Identification of polycyclicaromatic hydrocarbon is carried by gas chromatography alone in conjunction with mass spectrometry.
Quantitative determination is achieved by addition of known amounts of standard
compounds using flame ionization and multiple ion detectors.
Robbat et al [73] carried out on-site detection of polycyclic aromatic hydrocarbons
in hexane extract of sediments using thermal desorption gas chromatography-mass
spectrometry.
Real time aerosol mass spectrometry has been used to determine surface bound
PAHs in petroleum contaminated sediments [74].
Bjorseth et al [12] described a capillary gas chromatographic method for determining polyaromatic hydrocarbons in sediments. Up to 34 polyaromatic hydrocarbons
were identified, some carcinogenic.
Giger and Schnaffer et al [10] described a glass capillary gas chromatographic
method for determination of polycyclicaromatic hydrocarbons in lake and river sediments. Polycyclicaromatic hydrocarbons are isolated by a sequence of solvent extraction, gel filtration, and adsorption chromatography, and individual concentrations
determined by gas chromatography.
Readman et al [72] used flame ionisation capillary gas chromatography to determine polyaromatic hydrocarbons in extracts of rivers Mersey, Dee and Tamar estuary
sediments.
High-performance liquid chromatography
Marcomini et al [80] applied gradient elution reversed-phase high-performance liquid
chromatography coupled with a variable wavelength adsorption detector to 23 selected
polycyclic hydrocarbons (including most of those on the Environmental Protection
Agency priority pollutant list) in radon dated sediment core. Compounds, which
were not separated by chromatography were adequately resolved and quantified by
performing three runs per analysis using characteristic UV-visible absorption maxima. Detection limits ranged from 0.1 to 1 µg kg
−1 dry weight, and the average
recovery in spiking experiments was approximately 87%, with the lowest yield for
naphthalene (56%).
Supercritical fluid chromatography
Langenfeld et al [81] studied the effect of temperature and pressure on supercritical
fluid extraction efficiencies of polycyclicaromatic hydrocarbons and polychlorobiphenyls in river sediments. At 50
◦ C, raising the pressure.
Langenfeld et al [81] also compared supercritical monochlorofluoromethane,
nitrogen dioxide and carbon dioxide for the extraction of polycyclicaromatic
hydrocarbons from sediments. Monochlorodfluoromethane provided the highest
recoveries.
Gas chromatography-mass spectrometry
Tan et al [71] devised a rapid simple sample preparation technique for analysis
polycyclicaromatic hydrocarbons in sediments. Polycyclicaromatic hydrocarbons are
removed from sediment by ultrasound extraction and isolated by solvent partition
and silica gel column chromatography. The sulphur removal step is combined into
the ultrasonic extraction procedure. Identification of polycyclicaromatic hydrocarbon is carried by gas chromatography alone in conjunction with mass spectrometry.
Quantitative determination is achieved by addition of known amounts of standard
compounds using flame ionization and multiple ion detectors.
Robbat et al [73] carried out on-site detection of polycyclic aromatic hydrocarbons
in hexane extract of sediments using thermal desorption gas chromatography-mass
spectrometry.
Real time aerosol mass spectrometry has been used to determine surface bound
PAHs in petroleum contaminated sediments [74].
Bjorseth et al [12] described a capillary gas chromatographic method for determining polyaromatic hydrocarbons in sediments. Up to 34 polyaromatic hydrocarbons
were identified, some carcinogenic.
Giger and Schnaffer et al [10] described a glass capillary gas chromatographic
method for determination of polycyclicaromatic hydrocarbons in lake and river sediments. Polycyclicaromatic hydrocarbons are isolated by a sequence of solvent extraction, gel filtration, and adsorption chromatography, and individual concentrations
determined by gas chromatography.
Readman et al [72] used flame ionisation capillary gas chromatography to determine polyaromatic hydrocarbons in extracts of rivers Mersey, Dee and Tamar estuary
sediments.
High-performance liquid chromatography
Marcomini et al [80] applied gradient elution reversed-phase high-performance liquid
chromatography coupled with a variable wavelength adsorption detector to 23 selected
polycyclic hydrocarbons (including most of those on the Environmental Protection
Agency priority pollutant list) in radon dated sediment core. Compounds, which
were not separated by chromatography were adequately resolved and quantified by
performing three runs per analysis using characteristic UV-visible absorption maxima. Detection limits ranged from 0.1 to 1 µg kg
−1 dry weight, and the average
recovery in spiking experiments was approximately 87%, with the lowest yield for
naphthalene (56%).
Supercritical fluid chromatography
Langenfeld et al [81] studied the effect of temperature and pressure on supercritical
fluid extraction efficiencies of polycyclicaromatic hydrocarbons and polychlorobiphenyls in river sediments. At 50
◦ C, raising the pressure.
Langenfeld et al [81] also compared supercritical monochlorofluoromethane,
nitrogen dioxide and carbon dioxide for the extraction of polycyclicaromatic
hydrocarbons from sediments. Monochlorodfluoromethane provided the highest
recoveries.