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6.6.4 Procedure for the analysis of Chlorpyrifos, Endosulfan and 
Trifluralin in sediment 
The sediments were dried at room temperature for 72 h and ground (centrifugal force 
ball mill (Retsch) 15 min, 50rmp). Before microwave assisted extraction (MAE), D14- 
Trifluralin, Dio-Chlorpyrifos-ethyl and D^Endosulfan I were added as internal 
standards (0.1 pg/kg) to 40 g sediment. The sediment was mixed with 0.5 g activated 
copper powder to remove sulphur. Hot extraction was accomplished in a microwave 
system (pPrep-A, MLS, 10 min; 100°C) using acetone/n-hexane (75/25 v/v) as solvent. 
During extraction the sediment was stirred. After cooling, the solution was separated 
from the sediment by filtration (filtration unit 30 mL from sartorius; glass microfibre 
filter (whatman, 25 mm GF/A; heated at 500°C for 3 h)). The extraction was carried out 
twice. Both extracts were combined and the solvent was changed to n-hexane. The 
extracts were cleaned up on silica gel (silica gel 60, Merck, Darmstadt; heated for 2 h at 
150°C, deactivated with 6 % w/w water). Elution was done with n- 
hexane/dichloromethane (50/50 v/v) and pure dichloromethane. The solvent of both 
fractions was changed to «-hexane, and D6-chlorpyrifos-methyl was added as recovery 
standard (0.1 pg/kg). The first fraction generally contained all target compounds. It was 
concentrated to 300 pi and analysed by GC-MS (see 6.6.2). 
6.6.5 Procedure for the analysis of Chlorpyrifos, Endosulfan and 
Trifluralin in fish liver 
After preparation, the liver samples were stored at -20°C. The tissue was thawed at 
room temperature before analysis. All liver tissue (ca. 1-4 g ww) was used for sample 
preparation. Before freeze drying at 1.3mbar for 48 h (Steris, Lyovac GT2) D14- 
Trifluralin, Dio-Chlorpyrifos-ethyl and D4-Endosulfan I were added as internal 
standards (1.3 pg/kg ww). Hot extraction was accomplished in a microwave oven 
(10 min; 100°C) using acctonc/77-hcxanc (75/25 v/v) as solvent. During the extraction 
the samples were stirred. After cooling the solution was separated from the tissue by 
filtration (filtration unit 30 mL from sartorius; glass microfibre filter (whatman, 25 mm 
GF/A; heated at 500°C for 3 h)). The extraction was carried out twice. Both extracts 
were combined and the solvent removed in a smooth nitrogen stream and the lipid