Agilent Technologies 7200 Operation Manual page 84

4 Operating in Chemical Ionization (CI) Mode
To Switch from the EI Mode to CI Mode
84
Table 8 Default Tune Control Limits, used by CI autotune only
Reagent gas
Ion polarity
Abundance target
Peakwidth target
Maximum repeller
Maximum emission
current, µA
Max electron energy, eV
Notes for Table 8:
• N/A Not available.
• Abundance target Adjust higher or lower to get desired
signal abundance. Higher signal abundance also gives higher
noise abundance.
• Peakwidth target Higher peakwidth values give better
sensitivity, lower values give better resolution.
• Maximum emission current Optimum emission current
maximum for NCI is very compound-specific and must be
selected empirically. Optimum emission current for
pesticides, for example, may be about 200 µA.
Methane
Positive Negative
6 6
1x10 1x10
0.7 0.7
4 4
240 50
240 240
Ammonia
Positive Negative
6
N/A 1x10
N/A 0.7
N/A 4
N/A 50
N/A 240
Operation Manual