Organics
57
alpha and gamma hexachlorocyclohexanes and dichlorobenzenes in amounts down to
0.5 J..lgkg- I in the sediment [118-120]. Lee [121] used capillary gas chromatography
with electron capture detection to determine down to 0.002 mg kg-I of chloroanisoles
and 2-chloromethylanisoles in hexane-acetone extracts of river sediments. Wegman
and Greve [122] have described a microcoulometric method for determining extractable organic halogen compounds in sediments. Schellenberg et al. [134] studied the
adsorption of chlorophenols on sediments. Lee et al. [138] described an acetonehexane extraction procedure followed by electron capture gas chromatography for the
determination of down to 1 J..lg kg-I chlorinated phenols in sediments.
Onuska and Terry [142] have described a method for the determination of chlorinated benzenes in bottom sediment deposits. Sample preparation methods using
Soxhlet extraction, ultrasonic extraction or steam distillation were compared. The
chlorinated benzenes were characterized by open tubular column gas chromatography with electron capture detection. In recovery studies using sediments with different organic matter contents, the steam distillation method was the most efficient.
Detection limits were in the range 0.4-10 J..lg kg-I.
2.4.11
Chlorinated Insecticides
Sackmauereva et al. [123] described a gas chromatographic method for the determination of chlorinated insecticides (BHC isomers, DDE, DDT) and hexachlorobenzene
in petroleum ether extracts of river sediments in a rotary film evaporator. Recoveries
of the aforementioned compounds were in the range 86-106 %.
Suzuki et al. [124, 125] studied the determination of chlorinated insecticides in
hexane extracts of river sediments using high resolution gas chromatography with
glass capillary columns. Minimum detectable levels of a-BHC, fi-BHC, y-BHC,
(j -BHC, heptachlor, heptachlor epoxide, aldrin, dieldrin, endrin, p,p' -DDE, p,p' -TDE,
and p,p' -DDT in 100 g samples of bottom sediment were 0.0005, 0.0032, 0.0014,
0.0040,0.0012,0.0020, 0.0014, 0.0020, 0.0056, 0.0032, 0.0080 and 0.0120 mg kg-I, respectively.
Woodham et al. [126] converted dieldrin and endrin to chemical derivatives prior
to gas chromatographic determination of these substances in hexane extracts of sediments.
Goldberg [127] studied the relationship between pesticide concentrations in water
and in sediments and its dependence on the specific surface area of the sediment.
Lopez Avila et al. [730] have described a microwave assisted extraction procedure
for the separation of chlorinated insecticides from sediments.
Snyder et al. [733] compared supercritical extraction with classical sonication and
Soxhlet extraction for selected pesticides and applied the procedure to river sediments. Samples extracted with supercritical carbon dioxide modified with 3 % methonil at 350 atm and 50°C gave ~ 85 % recovery of organochlorine insecticides including dichlorous, diazinon, endrin, endrin aldehyde, decachlorobiphenyl, p,p' -DDT
and Mirex.
Grob et al. [756] compared supercritical extraction with classical sonication and
Soxhlet extraction from river sediment for selected organochlorine insecticides
57
alpha and gamma hexachlorocyclohexanes and dichlorobenzenes in amounts down to
0.5 J..lgkg- I in the sediment [118-120]. Lee [121] used capillary gas chromatography
with electron capture detection to determine down to 0.002 mg kg-I of chloroanisoles
and 2-chloromethylanisoles in hexane-acetone extracts of river sediments. Wegman
and Greve [122] have described a microcoulometric method for determining extractable organic halogen compounds in sediments. Schellenberg et al. [134] studied the
adsorption of chlorophenols on sediments. Lee et al. [138] described an acetonehexane extraction procedure followed by electron capture gas chromatography for the
determination of down to 1 J..lg kg-I chlorinated phenols in sediments.
Onuska and Terry [142] have described a method for the determination of chlorinated benzenes in bottom sediment deposits. Sample preparation methods using
Soxhlet extraction, ultrasonic extraction or steam distillation were compared. The
chlorinated benzenes were characterized by open tubular column gas chromatography with electron capture detection. In recovery studies using sediments with different organic matter contents, the steam distillation method was the most efficient.
Detection limits were in the range 0.4-10 J..lg kg-I.
2.4.11
Chlorinated Insecticides
Sackmauereva et al. [123] described a gas chromatographic method for the determination of chlorinated insecticides (BHC isomers, DDE, DDT) and hexachlorobenzene
in petroleum ether extracts of river sediments in a rotary film evaporator. Recoveries
of the aforementioned compounds were in the range 86-106 %.
Suzuki et al. [124, 125] studied the determination of chlorinated insecticides in
hexane extracts of river sediments using high resolution gas chromatography with
glass capillary columns. Minimum detectable levels of a-BHC, fi-BHC, y-BHC,
(j -BHC, heptachlor, heptachlor epoxide, aldrin, dieldrin, endrin, p,p' -DDE, p,p' -TDE,
and p,p' -DDT in 100 g samples of bottom sediment were 0.0005, 0.0032, 0.0014,
0.0040,0.0012,0.0020, 0.0014, 0.0020, 0.0056, 0.0032, 0.0080 and 0.0120 mg kg-I, respectively.
Woodham et al. [126] converted dieldrin and endrin to chemical derivatives prior
to gas chromatographic determination of these substances in hexane extracts of sediments.
Goldberg [127] studied the relationship between pesticide concentrations in water
and in sediments and its dependence on the specific surface area of the sediment.
Lopez Avila et al. [730] have described a microwave assisted extraction procedure
for the separation of chlorinated insecticides from sediments.
Snyder et al. [733] compared supercritical extraction with classical sonication and
Soxhlet extraction for selected pesticides and applied the procedure to river sediments. Samples extracted with supercritical carbon dioxide modified with 3 % methonil at 350 atm and 50°C gave ~ 85 % recovery of organochlorine insecticides including dichlorous, diazinon, endrin, endrin aldehyde, decachlorobiphenyl, p,p' -DDT
and Mirex.
Grob et al. [756] compared supercritical extraction with classical sonication and
Soxhlet extraction from river sediment for selected organochlorine insecticides