Introducing the MSQ
_______________________________________________ The Source–An Introduction to API Techniques
HO
HO
OH
NH
2
+
tBu
50
75
100
125
150
175
200
225
250
275
300
m/z
0
100
%
240
241
50
75
100
125
150
175
200
225
250
275
300
m/z
0
100
%
240
222
241
50
75
100
125
150
175
200
225
250
275
300
m/z
0
100
%
240
222
148 166
241
[M+H]
+
Source voltage 10V
HO
HO
NH
2
+
tBu
[M+H]
+
-H
2
O
Source voltage 25V
Source voltage 35V
HO
HO
NH
3
+
[M+H]
+
-H
2
O-tBu
Protonated molecule at m/z 240
Fragment ion at m/z 222
Fragment ion at m/z 166
Figure 1-14. Source fragmentation of salbutamol in electrospray
ionization
Optimum Response for Confirmatory Ions
When acquiring fragment ions for confirmation purposes, the applied source
voltage per compound would require some optimization to maximize the
intensity of these ions. It is generally observed that small changes to the
source voltage result in only small intensity changes; thus, fine-tuning of
this voltage is usually not critical (typ/- 5 V is adequate).
___________________________MSQ Hardware Manual ___________________________
1-17
