(2) Samples of the cargo oil were taken for: 



a. analysis of chemical composition for reference to future 

 samples and for weathering studies 



b. determination of the physical chemistry of the oil 



B. Water column studies 



(1) Lagrangian drift samples (repetitive sampling of a dyed parcel 

 of water) to determine dispersion of subsurface oil down-current 

 from a contained surface slick. 



(2) Eulerian sampling at biological stations established by the 

 Swedish scientists, to determine concentrations at various 

 times . 



(3) Water column samples in an area known to have been heavily 

 polluted and since blown clear of floating oil, to determine 

 subsurface hydrocarbons remaining several days after the 

 passage of a floating oil slick. 



(4) Water column samples below a moving oil slick (emulsion) to 

 determine waterborne hydrocarbons. 



(5) Filtration of various samples to determine particle size 

 distributions of accommodated oil under various conditions. 



(6) Extraction of selected split samples with both hexane and 

 CC£, , to compare methodologies of UV-fluorescence . 



C. Aerial mapping of visible floating oil, concurrent with sampling. 



5.2 Hydrocarbon analysis associated with the Tsesis oil spill 



During the NOAA team response, petroleum samples were collected, 

 and duplicate sets were distributed to Energy Resources Company, Inc. 

 (ERCO) and the Northwest and Alaska Fisheries Center (NWAFC). This 

 section describes the analysis performed at the NWAFC (information from 

 the ERCO set is reported in Chapter 11). 



Although the water content of the mousse samples varied from 12% to 

 76% by volume (Table 5.2.1), the normal paraffin distribution of the 

 water-free oil fraction of all three of the mousse samples was identical, 

 within experimental accuracy, to the cargo sample (Table 5.2.2). The 

 cargo sample had been collected after the oil had been off-loaded from 

 the Tsesis and shipped to its original destination at Sodertalje. The 



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