236
Sea and River Weeds
yielded at 85.6-94 %, 90-93.2 %, 90-102.4 %, and 92-105.8 % from plants. Purification on a Florisil column was used when determining chlorinated insecticides unstable at low pH (aldrin, dieldrin). The type and activity of Florisil influence the yield and
accuracy of the method. Therefore, the activity of this adsorbent had to be verified
and adjusted [686,687,690]. The average content of the y isomer of BHC found in
water plants was 0.026 mg kg-I while the ~ isomer was not present at 0.00 mg kg-I, Y +
o at 0.032 mg kg-I, DDE at 0.003 mg kg-I and DDT at 0.002 mg kg-I. These results
suggest that chlorinated insecticides, due to their physical and chemical properties,
can accumulate and adsorb onto solid particles.
10.1.3
Polychlorinated Biphenyls
Photoactivated luminesceance spectroscopy has been used as a method for the rapid
screening of polychlorobiphenyls in Biota [749].
10.5
Organometallic Compounds
10.5.1
Lead
The gas chromatography atomic absorption spectrometric procedure [159], described
under organolead compounds in Sect. 2.5.1 for the analysis of river sediments, has
been applied to the analysis of aquatic weeds taken in the St Lawrence River, Ontario.
Low concentrations of alkyllead compounds found in macrophytes taken 4 m deep in
the water were as follows; Me 3 EtPb 0.038 mg kg-I, MezEtzPb 1.50 mg kg-I, MeEt 3 Pb
3.61 mgkg-I, Et 4 Pb 16.5 mgkg-I, Et 3 Pb+ 0.59 mgkg-I, Me 3 Pb+ 0.11 mgkg-I, and total
lead 59.2 mg kg-I.
Surface macrophytes samples had lower alkyl lead contents, e. g. Et 4 Pb 0.07 mg
kg-I, Et 3 Pb+ 0.13 mg kg-I, and total lead 4.3 mg kg-I.
10.5.2
Tin
Francois and Weber [689] used hydride generation atomic absorption spectrometry
to speciate and determine methyltin and butyltin compounds in eelgrass (Zostera
marina L) leaf tissue from Great Bay estuaries, New Hampshire.
Extraction with hydrochloric acid yielded 63-87 % recoveries of methyltin, monoand dibutyltin. Hydride formation with sodium borohydride was effective. Tributyltin
was extracted with dichloromethane-methanol giving 77 % recovery, and detection
was improved by using tetrabutylammonium borohydride for hydride formation.
Analysis of eelgrass samples indicated minimal pollution by methyl- and butyltin
compounds, and results from an experimental mesocosm suggested that determination of butyl tin concentrations in seagrass tissue could provide a sensitive method for
detecting low levels of butyl tin contamination in the aquatic environment.
Sea and River Weeds
yielded at 85.6-94 %, 90-93.2 %, 90-102.4 %, and 92-105.8 % from plants. Purification on a Florisil column was used when determining chlorinated insecticides unstable at low pH (aldrin, dieldrin). The type and activity of Florisil influence the yield and
accuracy of the method. Therefore, the activity of this adsorbent had to be verified
and adjusted [686,687,690]. The average content of the y isomer of BHC found in
water plants was 0.026 mg kg-I while the ~ isomer was not present at 0.00 mg kg-I, Y +
o at 0.032 mg kg-I, DDE at 0.003 mg kg-I and DDT at 0.002 mg kg-I. These results
suggest that chlorinated insecticides, due to their physical and chemical properties,
can accumulate and adsorb onto solid particles.
10.1.3
Polychlorinated Biphenyls
Photoactivated luminesceance spectroscopy has been used as a method for the rapid
screening of polychlorobiphenyls in Biota [749].
10.5
Organometallic Compounds
10.5.1
Lead
The gas chromatography atomic absorption spectrometric procedure [159], described
under organolead compounds in Sect. 2.5.1 for the analysis of river sediments, has
been applied to the analysis of aquatic weeds taken in the St Lawrence River, Ontario.
Low concentrations of alkyllead compounds found in macrophytes taken 4 m deep in
the water were as follows; Me 3 EtPb 0.038 mg kg-I, MezEtzPb 1.50 mg kg-I, MeEt 3 Pb
3.61 mgkg-I, Et 4 Pb 16.5 mgkg-I, Et 3 Pb+ 0.59 mgkg-I, Me 3 Pb+ 0.11 mgkg-I, and total
lead 59.2 mg kg-I.
Surface macrophytes samples had lower alkyl lead contents, e. g. Et 4 Pb 0.07 mg
kg-I, Et 3 Pb+ 0.13 mg kg-I, and total lead 4.3 mg kg-I.
10.5.2
Tin
Francois and Weber [689] used hydride generation atomic absorption spectrometry
to speciate and determine methyltin and butyltin compounds in eelgrass (Zostera
marina L) leaf tissue from Great Bay estuaries, New Hampshire.
Extraction with hydrochloric acid yielded 63-87 % recoveries of methyltin, monoand dibutyltin. Hydride formation with sodium borohydride was effective. Tributyltin
was extracted with dichloromethane-methanol giving 77 % recovery, and detection
was improved by using tetrabutylammonium borohydride for hydride formation.
Analysis of eelgrass samples indicated minimal pollution by methyl- and butyltin
compounds, and results from an experimental mesocosm suggested that determination of butyl tin concentrations in seagrass tissue could provide a sensitive method for
detecting low levels of butyl tin contamination in the aquatic environment.