How to Avoid Corona Discharge in Electrospray Ionization (ESI)

For research use only. Not for use in diagnostic procedures.

Answer

Corona discharge occurs at the tip of the ESI electrode when the ionization voltage exceeds a certain threshold in the negative ion mode. It creates a plasma/spark at the tip of the electrode which will prevent the formation of a spray and therefore no data will be collected at this time.
All sources which use ESI can be affected.
This can be avoided by considering the following:

• Use zero air for Gas 1 and Gas 2. Nitrogen will cause corona discharge at lower IS values
• Lower the IS values
• Lower the source temperature
• Change the vertical probe position to lower mm levels (will move probe upwards)