Page 236 - Advances in Forensic Applications of Mass Spectrometry - Jehuda Yinon

1522_book.fm Page 209 Thursday, November 13, 2003 9:58 AM

Chromatogram Plots
File: I:\data 0199\Tlle 4886.ms
Sample: 1.00M IN SAMPLING TIME, 5M IN DESORB, GB 5/1/99 12.27 PM
Sample Notes: F6-GASOLINE 1PPM
Operator: D.SUTHERLAND Scan Range: 1-2008 Time Range: 0.01-15.00 min.
Specl 1 7.097m In.scan: 1146 chan: 1 Ions: 37 us RIC: 10170939
BP 131 (30+8039-100%) Tlle 4886.ms 131
100%
75%
50%
146
25% 91 115
41 51 63 77 105
0%
Specl 2 7.959m In.scan: 1240 chan: 1 Ions: 34 us RIC: 11856453
BP 131 (2781796-100%) Tlle 4886.ms 131
100%
75%
50%
146
25% 41 57 71 91 115
0% 105 162
D Tll Specl 1 - Specl 2 7.097m In.scan: 1146 chan: 1 Ions: 37 us RIC: 10170939
100% Normalized 7.959m In.scan: 1240 chan: 1 Ions: 34 us RIC: 11856453
50%
0%
−50%
−100%
50 75 100 125 150 175 m/z 200
MCounts file+886.ms lons: 131 all
2.5
2.0
1.5
1.0
0.5
0.0
MCounts file 4886.ms lons: 146 all
0.75
0.50
0.25
0.00
6 7 8 9 minutes
3
1026 1135 1245 1354 scans
Figure 5.13 Comparison of GC/MS spectra for other indane isomers to the
first isomer: essentially identical.
GC/MS/MS analyses. Figure 5.12, Figure 5.13, and Figure 5.14 show the
GC/MS spectra from the series of indanes found in gasoline. The recon-
structed mass ion profiles of m/z 131 and 146 are shown for reference. The
top spectrum in each figure is for the isomer with the largest response for
the ion at m/z 131 (cursor with single flag). The second spectrum in Figure
5.12 is for the adjacent isomer in the ion chromatogram (cursor with a double
flag). The middle diagram in this figure shows the difference between these
two spectra and indicates that these two isomers have virtually identical
spectra, as expected, in this GC/MS analysis.
Figure 5.13 is laid out in the same way as Figure 5.12. Figure 5.13 also
illustrates that another isomer (cursor with a double flag) has an identical
spectrum to the first isomer. Figure 5.14 illustrates that a third isomer has a
spectrum nearly identical to the first isomer. The small deviation at m/z 133
in the spectrum is from another compound that is not fully separated from
this third isomer.

© 2004 by CRC Press LLC