11 
Fig. 3: Gas-chromatograms of light fuel samples showing differences in the parameters given 
in Fig. 2 (pristane and phytane are found between 5 and 5,5 minutes). 
2.1.1.2 GC-MS analysis (alternative parameters) 
As higher-boiling biomarkers are rarely present, there is no other way of comparing two light 
fuel oil samples in Oil Spill Identification than to go deeper into the groups of the remaining 
aromatic hydrocarbons and sulphur-containing aromatic compounds. 
Light fuel oil is subject to rapid weathering once it has been released into the environment. 
Therefore, it would not be appropriate to base general guidelines for the comparison of two 
light fuel oil samples on the lower-boiling compounds (such as decalines or low-boiling 
naphthalenes or thiophenes). Experience has shown that compounds from the higher-boiling 
end, i.e. the region between n-Ci9 and n-C25 (boiling range around 320 °C to 400 °C), are 
more generally suitable for light fuel oil comparisons (Fig. 4).