47 
The examples given above are mainly presented in order to show the presence and the 
position of peaks of compounds, which may have a “special” meaning in distinct oil spill 
cases. Generally, their rapid recognition may save resources, in case they are present in the 
spill sample but not in the comparison sample. On the other hand, their presence in both 
samples may indicate a much stronger connection between these samples than other 
compounds. 
A more detailed geochemical interpretation of the biomarker patterns of the world’s crude oils 
is beyond the scope of this contribution and beyond the scope of Oil Spill Identification. 
A substantial database of crude oils from all over the world is the prerequisite for the further 
classification of crude oils by their main production areas for Oil Spill Identification. 
3 Conclusion 
The meaning of compounds (or compound ratios) in oil samples is different from case to case, 
and a parameter set generally suitable for the verification of results in all oil spill cases might 
rarely exist. Whereas one single parameter may already be the decisive factor in a distinct 
case, other cases may require much more detailed investigations. 
However, some general rules exist with regard to different oil types and their occurrence and 
behaviour in the aquatic environment. 
The vast majority of oil spills in European waters originates from “normal” shipping 
operations. But when oil products or product mixtures, such as waste oils, are considered, the 
original meaning and the specificity of the pristine biomarker relations in crude oils are lost 
totally. The production (and or mixing) process plays the dominant role here. Care must thus 
be taken in order to avoid misinterpretation, when oil products are compared. Parameters may 
be similar or even identical simply because of the same production process. 
Therefore, a step-by-step procedure is provided for identifying the oil type, even in (highly) 
weathered samples, and guidance is given on how to handle oil parameters with respect to the 
different characteristics of oil types. 
It has finally been shown that monitoring of platforms and identifying crude oil pollution 
caused by tankers are quite different tasks. Different parameters may thus have a highly 
different meaning when crude oil pollution has to be identified. 
It must be kept in mind, generally, that Oil Spill Identification by chemical analysis is an 
important -sometimes the most important- instrument for providing evidence in criminal 
proceedings. Not knowing the type of oil, which was analyzed, does not only show