17 
Fig. 10: Steranes (mass-fragment 217) of different lubricating oils (same oils as in Fig. 8). 
Lower-boiling biomarkers such as the two C27-hopanes (Ts and Tm) and the two lower 
boiling diasteranes thus are more pronounced in lower-viscous lubricating oils, whereas the 
higher-boiling biomarkers are more pronounced in higher-viscous oils. 
Especially at this point, it becomes clear that the original meaning and the specificity of the 
pristine biomarker relations in crude oils are lost totally when oil products or product mixtures 
(waste oils, see 2.4) are considered. The production (and or mixing) process plays the 
dominant role here. As can be seen from Figure 10, for example, the important role of the 
diasterane/regular-sterane relation in crude oils, which is mainly a source indicator but 
influenced also by maturity, is definitely no longer valid in these cases. This relation is by far 
much more determined by the (viscosity-) type of the lubricating oil involved. 
One of the most significant findings for characterizing oil products is that aromatic steranes 
(mass fragment 231) are not present in commonly used lubricating oils (Fig. 11 and Fig. 12, 
see note).