15 
Oil Spill identification - Round Robin 20045 
One of the first two bilge samples was mixed 1:1 with one of the 
second two bilge samples and the remaining samples were also mixed 
1:1. The resulting mixtures represent the two source samples. 
To create the spill samples the mixture called Source I was weathered 
artificially. Two glass Petri dishes containing 2 g of the Source I mixture 
each stayed in a ventilated oven (Heraeus UT12) for 1,5 and 4 hours at 
a temperature of 75°C. The remaining oil was dissolved in 
dichloromethane and filtered over a glass fibre filter to remove small 
particles visible and, to be sure, dried with Na 2 S0 4 . 
The resulting "case" contains two source samples with a quite similar 
lubricating oil part and a different gas oil part. This is similar to the real 
situation on inland ships. The variation in base oil to produce 
lubricating oil is limited and the variation in lubricating products used 
on board is lower than the variation in gas oil used as fuel. 
1.4 Report 
Most results were received by email. One result had to be scanned. 
A combination of all data would result in a huge report. Therefore the 
report is published on CD. The individual results can be found on the 
CD, whereas in this final report of the Round Robin the information is 
summarized and commented in chapter 2 and discussed in chapter 3. 
On the CD also Part I and II of the concept of the European Guideline, 
as send to CEN for comments on 13-3-06, can be found. 
The results were not discussed in great detail with the intention that all 
individual reports are available and all participants can compare their 
own method with others. 
Reading and comparing the results of the participants was an 
instructive and valuable job. We hope that our comments and advices 
are appreciated and can help to improve also the knowledge about oil 
spill identification.