2000 MS Hardware Maintenance
38
Chemical Ionization Options
You are now ready to operate the system in the CI mode. If you are a new user,
we recommend that you perform the introductory example of CI operation in
tuning the Saturn for Chemical Ionization in
the Tutorial Manual.
Default Parameters for Gaseous CI Reagents
Reagent Gas
Methane
Isobutane Ammonia
CI Storage Level (m/z)
13
19
13
Ejection Amplitude (v)
9
15
9
Background Mass (m/z)
45
65
45
Target TIC
5000
5000
5000
Maximum Ionization Time (
µ
sec)
2000 2000 2000
Maximum Reaction Time (
µ
sec)
60 60 60
Prescan Ion Time (
µ
sec)
100 100 100
If you have installed the Liquid CI Inlet or the Multiple CI Module, the following
parameters may be used for standard liquid CI reagents.
Default Parameters for Liquid CI Reagents
Reagent Liquid
Acetonitrile d3-Acetonitrile Methanol
CI Storage Level (m/z)
19
19
19
Ejection Amplitude (v)
15
15
15
Background Mass
(m/z)
65 65 55
Target TIC
5000
5000
5000
Maximum Ionization
Time (
µ
sec)
2000 2000 2000
Maximum Reaction
Time (
µ
sec)
40 20* 40
Prescan Ion Time
(
µ
sec)
100 100 100
*
Use short reaction times for deuterated reagents. Longer reaction times allow
more H/D exchange with background water and the resulting spectrum will show
more [M+H]
+
and less [M+D]
+
.
