ELSD shows no peak - WKB81505

SYMPTOMS

• UV has peak, but no ELSD peak
• No leak discovered, nebulizer spray is good, exhaust is normal

ENVIRONMENT

• ACQUITY UPLC ELS Detector
• ACQUITY UPLC H-Class

CAUSE

The drain line was submerged in the waste container below waste solvent level, so nothing drained out and the drift tube was full of MP.

FIX or WORKAROUND

Trim the drain waste tubing shorter so that it will never become submerged in the waste container if it fills up.

ADDITIONAL INFORMATION

Nitrogen pressure was good. The ELSD passed all diagnostic tests, and exhaust was checked out. The scattering chamber was clean and the diode was not coated with residue.