Performance and results 
21 
Fig. 11: Overlaid mass chromatograms (Set 1, sample 1) of hopanes (top) and steranes (bottom) 
from RWS (red) and BSH (blue). 
Of the hopanes, nine representative substances were considered in this inves 
tigation as well as six of the steranes. Normalisation was performed to the 
highest peak in each group (hopanes: 29ab, steranes: 27bbR). As can be 
seen in the upper chromatogram in Fig. 11, both analyses are impacted by an 
increasing baseline (probably due to column bleeding). The further processing 
of the peak heights was done without any compensation for that Influence, 
which might have a negative effect on the CD- or RSD-features for the final 
comparison. Considering areas instead of peak heights, again, might be an 
option to resolve this problem. 
Anyway, absolute abundance of both groups of biomarkers is very low and 
consequently high RSDs are to be expected. 
The radar chart Fig. 12 clearly shows that the hopanes are more stable in 
terms of repeatability than the steranes, as the latter seem to be more difficult 
to analyse.