Low sensitivity in negative mode for lockspray and toxicology screening on Xevo G2-XS - WKB193985

SYMPTOMS

• Lockspray beam is a few thousand counts in negative for leucine enkephalin
• Lockspray beam is okay in positive mode for leucine enkephalin
• Samples are okay in positive mode but very poor in negative

ENVIRONMENT

• Xevo G2-XS

CAUSE

Arcing of the reference probe.

The reference probe is or has been partially blocked, and the capillary is protruding more than it should, causing arcing that affects negative mode specifically. 

FIX or WORKAROUND

Rebuild the reference probe.

ADDITIONAL INFORMATION

700004674 - ESI REFERENCE PROBE SERVICE KIT