To avoid excess liquid buildup in the ion source housing when you increase the liquid flow rate from the LC system, adjust the following parameters: gas flow rates (sheath, auxiliary, and sweep), ion transfer tube temperature, and vaporizer temperature.
For the APCI ion source, the recommended setting for the Corona Discharge Voltage depends on the polarity as follows:
- Positive Ion Discharge Current (μA): 4
- Negative Ion Discharge Current (μA): 10
The following table lists the recommended start settings for operating a system using a APCI configured API source with a range of LC solvent flow rates. The range for the Current LC Flow in the application is 0–3,000 µL/min.
LC Flow Rate (μL/min) | ≤14.99 | 15–99.99 | 100–199.99 | 200–499.99 | 500–999.99 | 1,000–3,000 |
|---|---|---|---|---|---|---|
Sheath Gas (Arb) | 10 | 15 | 25 | 45 | 45 | 45 |
Aux Gas (Arb) | 2 | 5 | 5 | 5 | 10 | 10 |
Sweep Gas (Arb) | 0 | 0 | 0 | 1 | 2 | 2 |
Ion Transfer Tube | 300 | 300 | 300 | 325 | 375 | 375 |
Vaporizer Temp (°C) | 0 | 275 | 325 | 350 | 400 | 400 |