To Perform Ci Autotune - HP 5973 MSD Hardware Manual

 CI operation
7R SHUIRUP &, DXWRWXQH

To perform CI autotune

After the reagent gas flow is adjusted, the lenses and electronics of the MSD should
be tuned. Perfluoro-5,8-dimethyl-3,6,9-trioxidodecane (PFDTD) is used as the
calibrant. Instead of flooding the entire vacuum chamber, the PFDTD is introduced
directly into the ionization chamber through the GC/MSD interface by means of the
gas flow control module.
C A U T I O N After the system has been switched from EI to CI mode, or vented for any other reason, the
MSD must be baked out for at least 2 hours before tuning. Longer bakeout is recommended
before running samples for optimal sensitivity.
There is a PCI autotune for methane only, as there are no PFDTD ions produced by
other gases in positive mode. PFDTD ions are visible in NCI for any reagent gas.
Always tune for methane PCI first regardless of which mode or reagent gas you wish
to use for your analysis.
Default (starting) CI tune parameters)
Reagent gas
Ion polarity Positive
150 µΑ
Emission
Electron energy 150 eV
Filament 1
Repeller 3 V
Ion focus 130 V
Entrance lens (gain) 0 mV/amu
Entrance lens offset 20V
EMVolts 1200
Gas Off Off
Gas select valve A
Suggested flow 20%
Source temp 250°C
Quad temp 106°C
Interface temp 320°C
Autotune Yes
56
Methane
Negative Positive
50 µΑ 150 µΑ
150eV 150eV
1 1
3 V 3 V
130 V 130 V
0 mV/amu 0 mV/amu
20 20V
1200 1200
Off Off
A B
40% 20
150°C 250°C
106°C 106°C
280°C 320°C
Yes No
Isobutane
Negative Positive
50 µΑ 150 µΑ
150eV 150eV
1 1
3 V 3 V
130 V 130 V
0 mV/amu 0mV/amu
20 20V
1200 1200
Off Off
B B
40 20
150°C 250°C
106°C 106°C
280°C 320°C
Yes No
Ammonia EI
Negative N/A
50 µΑ 35 µΑ
150eV 70
1 1 or 2
3 V 30 V
130 V 90 V
0 mV/amu 0 mV/amu
20 25
1200 1200
Off On
B N/A
40 N/A
150°C 230°C
106°C 150°C
280°C 280°C
Yes Yes