13 
Oil Spill identification - Round Robin 20045 
Extract I and II are from two samples from the water (dichloromethane 
extracts). 
Source I and II are bilges samples from two boats (pure oil). 
Samples from the surface water were taken in a canal in the Netherlands. An 
oil spill was located and a sample (Extract I) taken. The next day a second 
spill was found further on in the canal. Here also a sample was obtained 
(Extract II). Sailing records revealed that two boats could have caused the 
spills. From each boat a bilge sample was obtained (Source I and II). 
Question: Do samples match? (Extract I and/or Extract II with Source I and/or 
Source II). 
For convenience and to be sure that each participant becomes the same 
samples, the two spill samples have been extracted with dichloromethane and 
dried with Na 2 S04 
As indication: A dilution of the extract with a factor 8 will give a good signal 
on the GC-FID. 
It could be necessary to homogenize the bilge samples by stirring (or 
ultrasonic dispersion) prior to the analysis and to make a clean-up of these 
samples. 
The problems associated with the identification of bilge oil samples are 
especially well described in 
http://www.bsh.de/de/Produkte/Buecher/Berichte/Bericht31/Bericht31 .pdf. 
Hints, tips and precautions are given here concerning their analysis and result 
interpretation. 
Because the method of analysis is free, I would like to have a short 
description of the method, followed by a discussion about the results and 
where the conclusions are based on. Chromatograms are very welcome. If 
numbers are used for comparison (absolute concentrations, peak ratios), error 
handling should be included (see also RR 2004, Final Report). 
In the final report your original contribution will be present as annex. 
Therefore I have to ask you to send the results in a digital format by email. 
The main part of the report will be small and give a summary of the results. 
I will send you a concept and make it final after receiving your reactions. 
Time schedule: 
Start of August: Delivery of the samples. 
August/September: Reports have been returned. 
October: Final report will be sent to the participants. 
1.3 Sample preparation 
In RR2004 three gas oil samples from a real case were used. The 
"solution" to this case was not known, which was regarded as a 
disadvantage by some of the participants. 
This year a different type of oil was taken and to be able to know the 
answer, the samples were artificial prepared.