HP 5973 MSD Hardware Manual page 53

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Default Tune Control Limits (used by CI autotune only. These limits should not be confused with the parameters
set in Edit MS Parameters, or with those appearing on the tune report.)
Reagent gas
Ion polarity
b
Abundance target ,
d
Peakwidth target
Maximum repeller
Maximum emission current
Max electron energy, eV
a. Always set up in PCI with methane first, then switch to your desired ion polarity and gas.
b. Adjust higher or lower to get desired signal abundance. Higher signal abundance also gives higher noise abun-
dance. This is adjusted for data acquisition by setting the EMV in the method.
c. There are no PFDTD ions formed in PCI with any reagent gas but methane, hence, CI autotune is not available with
these configurations.
d. Higher peakwidth values give better sensitivity, lower values give better resolution.
e. Optimum emission current maximum for NCI is very compound-specific, and must be selected empirically. Opti-
mum emission current for pesticides, for example, may be about 200µA.
Methane
Positive Negative
6 6
1x10 1x10
0.6 0.6
4 4
e
240 50
240 240
a
Isobutane
a
a
Positive Negative
c
N/A 1x10
c
N/A 0.6
c
N/A 4
c
N/A 50
c
N/A 240
 CI operation
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Ammonia
a a
Positive Negative
6 c
N/A 1x10
c
N/A 0.6
c
N/A 4
c
N/A 50
c
N/A 240
a
a
6
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