24 Oil Spill identification - Round Robin 20045 
Oil spill identification samples from inland waters and the North Sea are 
analyzed according the concept guideline Part 2 of CEN BT/TF 120. 
In general: Samples are analyzed in duplicate with GC-FID. After 
assessment of the results the (probably) matching samples are also 
analyzed with GC-MS in SIM mode. 
After a visual assessment of the chromatograms (probably) matching 
samples are integrated for a large range of compounds (depending on 
the type of oil and compounds available). Ratios between spill and 
source samples are compared by using the repeatability limit (ISO 
5725) as a match criterion. 
=> 
Extract I 
match 
non-match 
Extract II 
match 
non-match 
Source I 
Source II 
Notes/remarks: 
RIZA has diluted the Sintef mixture for peak recognition a factor of 3 
with DCM and has analyzed the diluted mixture 8 times in order to 
calculate the RSD for the mixture at the given concentration. 
The results can be found on the CD in file St Sintef ratio validation.xls. 
In the guideline it is stated that the RSD should be equal or lower than 
5% during validation of the method. This is valid for all ratios with the 
ratio DR-30d/30ab at limit. 
2.10 Sintef 
Contacts: K.R. Sorheim, L-G. Faksness and P.S. Daling. 
Sintef http://www.sintef.no/ is a large Norwegian engineering institute 
and is among others active in the petroleum industry and petroleum 
research. Sintef analyzes all oil spill samples for the Norwegian 
government. 
As a basis for this oil spill fingerprinting case, SINTEF has used the 
presently draft version, August 2005, of the "CEN/BT/TaskForce 120 
Oil Spill Identification": Part 2 Analytical methodology and 
interpretation of results" 
Sintef analyzed the RR-samples with GC-FID and with GC-MS in SIM 
mode on PAH's and biomarkers. The resulting chromatograms are first 
evaluated visually and when a possible match is assumed a series of 
ratios are statistically compared. 
=> Extract I and II: Positive match between the spill samples. 
The spill samples are from the same source 
Source I: Positive match to the spills (Extract I and Extract II) 
Source II: Non-match to the spills (Extract I and Extract II)