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Line 64: − Figure 8-22 shows MRM output for steranes from the Lufa oil seep in Papua New Guinea. The same sample was also discussed on page 8–27. Each fragmentogram monitors the transformation of a particular molecular ion to the designated daughter ion. The top four traces monitor conversion to the m/z 217 fragment ion from four different sizes of original sterane molecules. The top chromatogram represents the decomposition of methylsteranes (molecular weight = 414 daltons), and through its very low relative intensity at 100% scale (1.7) shows these compounds to be present in minor amounts. The next three chromatograms are for the C<sub>29</sub>, C<sub>28</sub>, and C<sub>27</sub> steranes, respectively. From the relative concentrations (24.4, 10.6, and 15.8) of these fragments, we see the C<sub>29</sub> species is dominant. The fifth chromatogram monitors 4-methylsteranes, which in this sample represent only minor components. The last two fragmentograms, in contrast, monitor two different bicadinane species. − + + +
Gas chromatography/mass spectrometry (GC/MS): procedures (view source)
Revision as of 21:04, 10 February 2014
, 21:04, 10 February 2014→Example of MRM
==Example of MRM==
==Example of MRM==
[[file:oiloil-and-oilsource-rock-correlations_fig8-22.png|thumb|{{figure number|8-22}}. Copyright: Murray et al. (1993); courtesy Australian Geological Survey Organization.]]
[[file:oiloil-and-oilsource-rock-correlations_fig8-22.png|thumb|{{figure number|2}}. Copyright: Murray et al. (1993); courtesy Australian Geological Survey Organization.]]
[[:file:oiloil-and-oilsource-rock-correlations_fig8-22.png|Figure 2]] shows MRM output for steranes from the Lufa oil seep in Papua New Guinea. The same sample was also discussed on page 8–27. Each fragmentogram monitors the transformation of a particular molecular ion to the designated daughter ion. The top four traces monitor conversion to the m/z 217 fragment ion from four different sizes of original sterane molecules. The top chromatogram represents the decomposition of methylsteranes (molecular weight = 414 daltons), and through its very low relative intensity at 100% scale (1.7) shows these compounds to be present in minor amounts. The next three chromatograms are for the C<sub>29</sub>, C<sub>28</sub>, and C<sub>27</sub> steranes, respectively. From the relative concentrations (24.4, 10.6, and 15.8) of these fragments, we see the C<sub>29</sub> species is dominant. The fifth chromatogram monitors 4-methylsteranes, which in this sample represent only minor components. The last two fragmentograms, in contrast, monitor two different bicadinane species.
The presence of bicadinanes in this sample further limits the [[source rock]] age for this oleanane-bearing oil.
The presence of bicadinanes in this sample further limits the [[source rock]] age for this oleanane-bearing oil.