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Oil Spill identification - Round Robin 20045 
2.11 Swedish National Laboratory of Forensic Science 
(SKL) 
Contact: M. Kallberg 
SKL is the only forensic laboratory in Sweden and thus all kinds of 
investigations are performed, mainly to assist the police. The total 
number of persons employed is about 240. SKL has four departments: 
biology+morphology 
documents+IT 
drugs 
chemistry+technique+weapon. 
One group of nine persons is dealing with investigations related to fire, 
oil and environment. A big part of this is the analyses of oil samples in 
cases of fire-raising (e.g. gasoline and kerosene) and environmental 
contaminations. 
SKL does not (yet) have a home page on the Internet in English, they 
only have information in Swedish: http://www.skl.polisen.se/. 
The samples were analysed according to the standard procedure for oil 
investigation at the Swedish National Laboratory of Forensic Science. 
The method used is based on the "Nordtest method NT CHEM 001 
Edition 2" which may be found also in the Internet: 
http://www.nordicinnovation.net/nordtestfiler/chem001 .pdf 
The oil samples were diluted with dichloromethane and analysed with 
gas chromatography with flame ionisation detection. 
If there are differences between the samples that cannot be explained 
by weathering effects we conclude that the samples are not identical 
(have not been identical at the moment of discharge) and make no 
further investigations. 
If the results can be explained by weathering effects we continue by 
running the extracts on GC-MS in SIM mode 
=> According to the result of our analysis there is a positive match between 
spill samples (Extract I and II) and Source I. Between the spilled samples 
(Extract I and II) and the Source II there is a non-match. We express this in 
the same way as with other forensic comparisons, please see the last page of 
the SKL report. 
The findings show with certainty that the oil spill sample Extract I was 
identical with the bilge oil sample Source I at the time of discharge (Level 
+4). 
The findings strongly indicate that the oil spill sample Extract II was 
identical with the bilge oil sample Source I at the time of discharge (Level 
+3). 
The findings show with certainty that none of the oil spill samples 
Extract I or II were identical with the bilge oil sample Source II (Level - 
4).