74 Organic compounds in soils, sediments & sludges
Gas chromatography
Sattar and Paasivirta et al [78] have described a method for the analysis in soils of
MCPA (4-chloro-2-methyl phenoxy acetic acid herbicides) and two of its main metabolites, 4-chloro-o-cresol and 6-chloromethyl catechol by gas chromatography of the
pentafluorobenzyl derivatives [81, 82]. After derivitisation of the residue extract, a
clean-up procedure was applied. The best recoveries of compounds 74%–100% from
soil were obtained when the extraction was performed by shaking with ether-acetoneheptane-hexane (2:1:1:1) from acidified soil and when the clean-up was done by thin
layer chromatography. Detection limits were in the range of 2–25 ng absolute.
Renberg et al [77] has described a method for the determination of 2.4 dichlorophenoxy acetic acid (2.4D) and 2.4.5 tri chlorophenoxy acetic acid (2.4.5T) in soils in
which the herbicide is derivativized to methyl or 2-chloroethyl ester prior to determination by gas chromatography. Recoveries of the two herbicides at the 8–16 mg kg
−1
level in soil was between 70–74% (2.4D) and 84–86% (2.4.5T).
Waliszewski and Szynczynski et al [79] have described a gas chromatographic
method for the determination of 4-chloro-2-methyl phenoxy acetic acid(MCPA) and
2.4 chlorophenoxy acetic acid (2.4D) herbicides in soils. The chlorophenoxy acetic
acid herbicides were extracted from soil samples with dichloromethane. Sulphuric acid
was added. The extracts were esterified with 2,3,4,5,6-pentalfuorobenzylbromide and
extracted with petroleum ether. The levels of MCPA and 2,4-D were determined by gas
chromatography with electron capture detection. The detection limits were 0.5 µg kg
−1
2,4D in soil.
Lopez-Avila et al [80] used isotope dilution gas chromatography-mass spectrometry to determine low levels of µg kg
−1 , 2,4 dichlorophenoxy acetic acid herbicide in soil.
Stable labelled isotopes are spiked into samples before extraction and the ratio of
unlabelled compound and stable labelled isotope was used to quantitate the unlabelled
compound. Analysis is by high-resolution gas chromatography-mass spectrometry.
Compound concentrations ranged from 100 to 10 000 µg per kg for soil samples.
Average recoveries were over 84% and method precision given as relative standard
deviation, was better than 19%.
High-performance liquid chromatography
Di Corcia and Marchetto et al [83] determined chlorinated phenoxy acid and ester
type herbicides in amounts down to 1 mg kg
−1 or lower in soil by liquid chromatography combined with particle beam mass spectrometry and ultraviolet absorption
spectrometry.
Chlorinated [84–96] and 2, 4-diniltrophenoxy acid herbicides [87] have been determined. Liquid chromatography particle beam mass spectrometry has been used as an
analytical finish [85].
3.4 CARBAMATE TYPE INSECTICIDES
Gas chromatography
Cohen and Wheals et al [88] used a gas chromatograph equipped with an electron
capture detector to determine ten substituted urea and carbamate herbicides in soils
Gas chromatography
Sattar and Paasivirta et al [78] have described a method for the analysis in soils of
MCPA (4-chloro-2-methyl phenoxy acetic acid herbicides) and two of its main metabolites, 4-chloro-o-cresol and 6-chloromethyl catechol by gas chromatography of the
pentafluorobenzyl derivatives [81, 82]. After derivitisation of the residue extract, a
clean-up procedure was applied. The best recoveries of compounds 74%–100% from
soil were obtained when the extraction was performed by shaking with ether-acetoneheptane-hexane (2:1:1:1) from acidified soil and when the clean-up was done by thin
layer chromatography. Detection limits were in the range of 2–25 ng absolute.
Renberg et al [77] has described a method for the determination of 2.4 dichlorophenoxy acetic acid (2.4D) and 2.4.5 tri chlorophenoxy acetic acid (2.4.5T) in soils in
which the herbicide is derivativized to methyl or 2-chloroethyl ester prior to determination by gas chromatography. Recoveries of the two herbicides at the 8–16 mg kg
−1
level in soil was between 70–74% (2.4D) and 84–86% (2.4.5T).
Waliszewski and Szynczynski et al [79] have described a gas chromatographic
method for the determination of 4-chloro-2-methyl phenoxy acetic acid(MCPA) and
2.4 chlorophenoxy acetic acid (2.4D) herbicides in soils. The chlorophenoxy acetic
acid herbicides were extracted from soil samples with dichloromethane. Sulphuric acid
was added. The extracts were esterified with 2,3,4,5,6-pentalfuorobenzylbromide and
extracted with petroleum ether. The levels of MCPA and 2,4-D were determined by gas
chromatography with electron capture detection. The detection limits were 0.5 µg kg
−1
2,4D in soil.
Lopez-Avila et al [80] used isotope dilution gas chromatography-mass spectrometry to determine low levels of µg kg
−1 , 2,4 dichlorophenoxy acetic acid herbicide in soil.
Stable labelled isotopes are spiked into samples before extraction and the ratio of
unlabelled compound and stable labelled isotope was used to quantitate the unlabelled
compound. Analysis is by high-resolution gas chromatography-mass spectrometry.
Compound concentrations ranged from 100 to 10 000 µg per kg for soil samples.
Average recoveries were over 84% and method precision given as relative standard
deviation, was better than 19%.
High-performance liquid chromatography
Di Corcia and Marchetto et al [83] determined chlorinated phenoxy acid and ester
type herbicides in amounts down to 1 mg kg
−1 or lower in soil by liquid chromatography combined with particle beam mass spectrometry and ultraviolet absorption
spectrometry.
Chlorinated [84–96] and 2, 4-diniltrophenoxy acid herbicides [87] have been determined. Liquid chromatography particle beam mass spectrometry has been used as an
analytical finish [85].
3.4 CARBAMATE TYPE INSECTICIDES
Gas chromatography
Cohen and Wheals et al [88] used a gas chromatograph equipped with an electron
capture detector to determine ten substituted urea and carbamate herbicides in soils