An example of such a library search is illustrated in Fig. 5.15. Here, a measured
spectrum fits very well with the library proposal. A second library hit demonstrates
also some similarity but not a perfect fit. However, the concurrent appearance of
significant ions (here ions . . .) point to similar structural moieties (here the
phenysulfonic group). This exemplifies that also not perfectly fitting library
relative intensity
51
77
125
152
192
218
30
20
40 50 60
80
70
90 100 110 120 130
170
160
150
140
210
200
190
220 230
180
125
51
77
152
218
O
S
O
30
20
40 50 60
80
70
90 100 110 120 130
170
160
150
140
210
200
190
220 230
180
relative intensity
125
51
77
167
195
226
O
O
S
O
O
30
20
40 50 60
80
70
90 100 110 120 130
170
160
150
140
210
200
190
220 230
180
m/z
relative intensity
detected spectrum
125
77
218
125
226
77
Fig. 5.15 A detected mass spectrum and two mass spectra library hits. The first suggestion fits very
well, whereas the second exhibit significant differences. However, specific fragments of the second
suggestion also point to the phenyl sulfone moiety
116
5 GC/MS Data Evaluation