236 Organic compounds in soils, sediments & sludges
10.7.4 Triazine herbicides
Gas chromatography-mass fragmentography
The gas chromatography-mass fragmentography procedure has been used by
Karlhuber et al [178] to identify Atrazine residues in sewage. The samples were cleaned
up by the procedure of Ramsteiner et al [179]. An aliquot of sewage was neutralised
and extracted with dichloromethane.
Injection of sewage into a gas chromatograph equipped with mass fragmentographic detection showed up in the chromatogram at the retention time of Atrazine,
indicating that there was less than 0.01 µg L
−1 of Atrazine in the sewage.
This layer chromatography
Zawadzka et al [180] and Abbott et al [181] used thin layer chromatography to determine Simazine, Atrazine and Prometryne herbicides in sewage. After extraction of a
sample of sewage, with dichloromethane or diethyl ether at pH9, the organic extract
was condensed and applied to a column of basic aluminium oxide (activity 111) and the
herbicides were eluted with ether containing 0.5% of water. The eluate was condensed
and applied to a layer of silica gel G impregnated with fluorescein. The chromatograms
were developed with chloroform-acetone (9:1). The plates were dried, and the spots
were located by spraying with 0.5% Brilliant Green (C.I. Basic Green 1) in acetone
and exposing to bromine vapour. For samples containing 5–100 µg L
−1 of herbicide
the recoveries were between 83 and 97%.
High performance liquid chromatography
This procedure has been used to determine Aminocarb [182].
Mullins and Kirkbright et al [183] determined sodium N-methyldithiocarbamate
(Metham Sodium) and methyl isothiocyanate fungicides in untreated sewage by high
performance liquid chromatography using a micellar mobile phase and UV detection.
10.7.5 Phenoxy acetic and herbicide
Conversion to methyl esters followed by gas chromatography has been used to
determine phenoxyacetic acid herbicides in sewage sludge [184].
10.7.6 Mirex
Laseter et al [185] and Kaiser et al [186] have both utilised gas chromatography and
mass spectrometry for the determination of Mirex. Kaiser et al [186] has pointed
out that under standard gas chromatographic conditions, the Mirex peak is superimposed on that of the PCBs and, as a result, the presence of Mirex may have been
interpreted by several workers as a PCB isomer. He used a computer-controlled gas
chromatographic-mass spectrometer system to positively identify Mirex and distinguish it from other highly chlorinated insecticides that could have been present in
the samples including Aldrin, Chlordane, Dieldrin, Endrin, Endosulphan, Heptachlor,
Kepone (chlorodecone), Pentac and Toxaphene.
Andrade and Wheeler et al [18] have studied the biodegradation of Mirex (dechlorane C 10 H 12 ) by sewage sludge or organisms utilising
14 C-labelled Mirex). They did
not succeed in identifying the metabolites.
10.7.4 Triazine herbicides
Gas chromatography-mass fragmentography
The gas chromatography-mass fragmentography procedure has been used by
Karlhuber et al [178] to identify Atrazine residues in sewage. The samples were cleaned
up by the procedure of Ramsteiner et al [179]. An aliquot of sewage was neutralised
and extracted with dichloromethane.
Injection of sewage into a gas chromatograph equipped with mass fragmentographic detection showed up in the chromatogram at the retention time of Atrazine,
indicating that there was less than 0.01 µg L
−1 of Atrazine in the sewage.
This layer chromatography
Zawadzka et al [180] and Abbott et al [181] used thin layer chromatography to determine Simazine, Atrazine and Prometryne herbicides in sewage. After extraction of a
sample of sewage, with dichloromethane or diethyl ether at pH9, the organic extract
was condensed and applied to a column of basic aluminium oxide (activity 111) and the
herbicides were eluted with ether containing 0.5% of water. The eluate was condensed
and applied to a layer of silica gel G impregnated with fluorescein. The chromatograms
were developed with chloroform-acetone (9:1). The plates were dried, and the spots
were located by spraying with 0.5% Brilliant Green (C.I. Basic Green 1) in acetone
and exposing to bromine vapour. For samples containing 5–100 µg L
−1 of herbicide
the recoveries were between 83 and 97%.
High performance liquid chromatography
This procedure has been used to determine Aminocarb [182].
Mullins and Kirkbright et al [183] determined sodium N-methyldithiocarbamate
(Metham Sodium) and methyl isothiocyanate fungicides in untreated sewage by high
performance liquid chromatography using a micellar mobile phase and UV detection.
10.7.5 Phenoxy acetic and herbicide
Conversion to methyl esters followed by gas chromatography has been used to
determine phenoxyacetic acid herbicides in sewage sludge [184].
10.7.6 Mirex
Laseter et al [185] and Kaiser et al [186] have both utilised gas chromatography and
mass spectrometry for the determination of Mirex. Kaiser et al [186] has pointed
out that under standard gas chromatographic conditions, the Mirex peak is superimposed on that of the PCBs and, as a result, the presence of Mirex may have been
interpreted by several workers as a PCB isomer. He used a computer-controlled gas
chromatographic-mass spectrometer system to positively identify Mirex and distinguish it from other highly chlorinated insecticides that could have been present in
the samples including Aldrin, Chlordane, Dieldrin, Endrin, Endosulphan, Heptachlor,
Kepone (chlorodecone), Pentac and Toxaphene.
Andrade and Wheeler et al [18] have studied the biodegradation of Mirex (dechlorane C 10 H 12 ) by sewage sludge or organisms utilising
14 C-labelled Mirex). They did
not succeed in identifying the metabolites.