Organic compounds in non-saline sediments 147
isolated from Hudson river sediment dechlorinated most polychlorinated biphenyls
in Aroclor 1242 under anaerobic conditions in the laboratory. The higher the polychlorobiphenyl concentration, the more rapid the rate of dechlorination. The possible
mechanisms involved are discussed. The products of dechlorination were less toxic
than the original compounds and were more readily degraded by aerobic bacteria;
wastewater.
Muscalu et al [221] used GC × GCP-µ ECD to analyse mixtures of polychlorobiphenyls organochlorine pesticides and chlorobenzenes in sediments and sludges.
Gas chromatographic separation and identification of polychlorobiphenyls,
organochlorine pesticides and chlorobenzenes is one of the most common analyses performed by environmental laboratories. When using comprehensive two
dimensional gas chromatography (GC × GC) coupled with micro-electron capture
detector (µ-ECD), within- and between-compound class separations for the target
contaminants were achieved in a relatively short analysis time. With only a few coelutions present, the results showed that DB-1 × Rtx-polychlorobiphenyls is a powerful
column combination providing excellent chromatographic separation for polychlorobiphenyls/OCs/CBz standard mix. Reference materials and ‘real-life’ sediments and
sludges were analysed and the analytes quantified in these samples. The results were
compared to reference values and classical GC-ECD data where available. This method
was shown to be precise and accurate for the standard/reference materials tested and
is a feasible method for sediment and sludge sample analysis.
Results obtained in a comparison of GC-ECD and GC-GC µ ECD techniques
for the analysis of organo allurine pesticides are compared in Figure 6.4 comparable
results were obtained.
Gas chromatography-mass spectrometry
Eichelberger et al [128] applied gas chromatography-mass spectrometry, with computer controlled repetitive data acquisition from selected specific ions, to the analyses
of polychlorobiphenyls in lake sediments. The polychlorinated biphenyl mixtures were
separated by gas chromatography at 180
◦ C in a coiled glass column (180 cm × 2 cm)
packed with 1.5% OV-17 plus 1.95% QF-1 on Gas-Chrom Q (100–120 mesh), with
helium (30 ml min
−2 ) as carrier gas. Effluent is passed via a glass jet enrichment device
into a quadruple mass spectrometer controlled by a mini-computer in such a way that
only selected ions of specific m/e pass through the quadruple field. There is a substantial
gain in sensitivity, without loss of qualitative information contained in the complete
mass system. This technique provides a basis for a sensitive qualitative and quantitative (from ion-abundance chromatograms obtained from subset scanning) analysis for
polychlorinated biphenyls.
McMurtrey et al [40] investigated the feasibility of determining polychlorinated
biphenyls adsorbed on sediments by a procedure involving pyrolytic desorption at
1000
◦ C, followed by gas chromatography and mass spectrometry. The procedure was
capable of detecting polychlorinated biphenyls in sediment at the 10 mg kg
−1 level.
Robbat et al [130] evaluated a thermal desorption gas chromatographic-mass spectrometric technique for the detection of polychlorobiphenyls in sediments and soils.
Alford Stevens et al [129] have reported on an inter-laboratory study of the determination of polychlorinated biphenyls in environmental sediments. Electron capture
isolated from Hudson river sediment dechlorinated most polychlorinated biphenyls
in Aroclor 1242 under anaerobic conditions in the laboratory. The higher the polychlorobiphenyl concentration, the more rapid the rate of dechlorination. The possible
mechanisms involved are discussed. The products of dechlorination were less toxic
than the original compounds and were more readily degraded by aerobic bacteria;
wastewater.
Muscalu et al [221] used GC × GCP-µ ECD to analyse mixtures of polychlorobiphenyls organochlorine pesticides and chlorobenzenes in sediments and sludges.
Gas chromatographic separation and identification of polychlorobiphenyls,
organochlorine pesticides and chlorobenzenes is one of the most common analyses performed by environmental laboratories. When using comprehensive two
dimensional gas chromatography (GC × GC) coupled with micro-electron capture
detector (µ-ECD), within- and between-compound class separations for the target
contaminants were achieved in a relatively short analysis time. With only a few coelutions present, the results showed that DB-1 × Rtx-polychlorobiphenyls is a powerful
column combination providing excellent chromatographic separation for polychlorobiphenyls/OCs/CBz standard mix. Reference materials and ‘real-life’ sediments and
sludges were analysed and the analytes quantified in these samples. The results were
compared to reference values and classical GC-ECD data where available. This method
was shown to be precise and accurate for the standard/reference materials tested and
is a feasible method for sediment and sludge sample analysis.
Results obtained in a comparison of GC-ECD and GC-GC µ ECD techniques
for the analysis of organo allurine pesticides are compared in Figure 6.4 comparable
results were obtained.
Gas chromatography-mass spectrometry
Eichelberger et al [128] applied gas chromatography-mass spectrometry, with computer controlled repetitive data acquisition from selected specific ions, to the analyses
of polychlorobiphenyls in lake sediments. The polychlorinated biphenyl mixtures were
separated by gas chromatography at 180
◦ C in a coiled glass column (180 cm × 2 cm)
packed with 1.5% OV-17 plus 1.95% QF-1 on Gas-Chrom Q (100–120 mesh), with
helium (30 ml min
−2 ) as carrier gas. Effluent is passed via a glass jet enrichment device
into a quadruple mass spectrometer controlled by a mini-computer in such a way that
only selected ions of specific m/e pass through the quadruple field. There is a substantial
gain in sensitivity, without loss of qualitative information contained in the complete
mass system. This technique provides a basis for a sensitive qualitative and quantitative (from ion-abundance chromatograms obtained from subset scanning) analysis for
polychlorinated biphenyls.
McMurtrey et al [40] investigated the feasibility of determining polychlorinated
biphenyls adsorbed on sediments by a procedure involving pyrolytic desorption at
1000
◦ C, followed by gas chromatography and mass spectrometry. The procedure was
capable of detecting polychlorinated biphenyls in sediment at the 10 mg kg
−1 level.
Robbat et al [130] evaluated a thermal desorption gas chromatographic-mass spectrometric technique for the detection of polychlorobiphenyls in sediments and soils.
Alford Stevens et al [129] have reported on an inter-laboratory study of the determination of polychlorinated biphenyls in environmental sediments. Electron capture