Optimize Source and Gas Parameters and Voltage
Optimize ion source gas 1 (nebulizer gas) for the best signal stability and sensitivity. Ion source
gas 2 (heater gas) aids in the evaporation of solvent, which helps to increase the ionization of
the sample.
Too high a temperature can cause premature vaporization of the solvent at the tip of the
TurboIonSpray probe, especially if the probe protrudes too far, which results in signal instability
and a high chemical background noise. Similarly, a high heater gas flow can produce a noisy or
unstable signal.
Use the lowest ion source voltage possible without losing signal. In the Analyst software, this is
the
IonSpray Voltage
field. Focus on signal-to-noise and not just signal.
Note:
If the
IonSpray Voltage
is too high, then a corona discharge can occur. A corona
discharge is visible as a blue glow at the tip of the probe. It results in decreased sensitivity
and stability of the signal.
1. Adjust ion source gas 1 and ion source gas 2 in increments of 5 to achieve the best signal
or signal-to-noise ratio.
2. Increase the flow rate of the gas for the Curtain Gas interface until the signal begins to
decrease.
Note:
To prevent contamination, use the highest possible value for the flow rate of the gas
for the Curtain Gas interface that does not sacrifice sensitivity. Do not set the flow rate lower
than the values in the table:
. This helps to prevent penetration of the flow of the
gas for the Curtain Gas interface, which can produce a noisy signal; prevent contamination
of the aperture; and increase the overall signal-to-noise ratio.
Table 4-1 CUR Parameter Values
Mass Spectrometer
Starting Value
SCIEX 3200 systems
20
3. Adjust the ion source voltage in increments of 500 V to maximize signal-to-noise.
Optimize the Turbo Heater Temperature
The optimal heater temperature is dependent on the compound, flow rate, and mobile phase
composition. The higher the flow rate and the higher the aqueous composition, the higher the
optimized temperature.
When optimizing the source temperature, make sure that the ion source equilibrates to the new
temperature setting.
Ion Source Optimization
SCIEX 3200 Systems
44/114
System User Guide
RUO-IDV-05-6475-C
