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of Chlorpyrifos. Dicofol is included in two lists of the OSPAR Convention - the 
reference list of substances agreed at the 3 rd North Sea Conference (e.g. Annex ID to 
the Hague Declaration and the list of Potential Endocrine Disruptors - Part B). 
In addition, dicofol, endosulfan, PCP and Trifluralin are in the OSPAR list of 
substances for priority action. For all, “Background documents” have been published by 
the OSPAR Commission. Endosulfan, PCP and trifluralin are in the list of substances 
identified as of concern by HELCOM (1992) 
In order to obtain reliable monitoring data, analytical methods had to be developed and 
validated for ultratrace analysis with limits of detection in the low pg/L range for water, 
and in the ng/kg range for sediment and biota samples. 
Because of the intermediate polarity of the target compounds, all three compartments - 
water, sediment and biota - had to be investigated in order to obtain a comprehensive 
overview of the occurrence of these pesticides in the marine environment. 
To achieve that goal, representative sampling of water and sediment had to be carried 
out by the BSH in the North Sea and Baltic Sea. Samples were taken during routine 
monitoring surveys of the Bund/Lander-Messprogramm (BLMP). Biota (fish) sampling 
was carried out by Dr. M. Haarich during monitoring surveys of the 
Bundesforschungsanstalt fur Fischerei (BfA-Fi) . 
6.2 Survey of Properties of the Target Compounds 
6.2.1 Chlorpyrifos-ethyl and -methyl 
Figure 24: Structures of Chlorpyrifos-ethyl (A), -methyl (B) and their main metabolite 3,5,6-Trichloro-2- 
pyridinol (TCPy) (C)