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Oil Spill identification - Round Robin 20045 
3.Discussion 
Remark 
Similar lubricating oil In bilge samples Is 
often found by RIZA. This may be due 
to the fact that RIZA mainly receives 
cases from inland waters, where smaller 
ships with diesel driven engines are 
involved (In a limited area). BSH's 
experience is different: receiving mainly 
open sea and coastal cases quite 
different lubricating oils are found, even 
with regard to viscosity. 
3.1 Introduction 
In contrast to Round Robin tests, where the concentrations of single 
compounds have to be measured (part of the QM in environmental 
monitoring) it is merely asked for a conclusion (mainly "yes" or “no") 
in the RR-tests for oil spill identification. But the participants put much 
work into analysis and presentation. Thus, in addition to simply 
summarizing the mere "overall results" in a final RR-report, emphasis 
should also be put here on how results are achieved and how these 
results are presented. 
This RR offers a variety of possibilities to check the applied method and 
to make improvements towards a better effectiveness of the analysis 
and a better clarity of the report: 
1. The samples source I and source II contained different light fuel 
oils. 
2. Weathering was effective in the samples in the order: source I 
(no weathering) < spill I < spill II. 
3. In order to make the comparison not too easy, samples with 
very similar lubricating oil were chosen as possible source samples. The 
“true" biomarkers, i.e. hopanes and steranes, which originate from the 
lub oil, were thus hardly different in all 4 samples. 
4. The aromatic steranes, except maybe the two lightest boiling 
ones, i.e. C20, C21, were not present. 
The results of this Round Robin were jointly evaluated by RIZA and 
BSH. 
Although RIZA has prepared the samples and thus knows the result 
from the beginning, RIZA "participated" in this Round Robin even in a 
twofold way: 
Firstly, samples were analyzed and results (raw data) were produced 
ready for being included into the COSI database of the BSH. BSH has 
included them afterwards, (see for a presentation of COSI on the CD 
for Oeldatenbank- COSI.ppt or use 
http://www.bsh.de/de/Meeresdaten/Umweltschutz/Oelidentifizierung 
/Oeldatenbank.ppt) 
Secondly RIZA has produced results according to the draft CEN- 
guidelines. 
On the other hand, BSH has received 4 samples without knowing 
anything about them before the main part of this discussion was 
already written. There was merely the information that there were two