Low-volume injections give no peaks on Arc system - WKB201523

SYMPTOMS

• Loss of peaks when injecting low-volume (1 µL) injections  

ENVIRONMENT

• ACQUITY Arc Sample Manager FTN-R

CAUSE

The PEEK union that connects the PEEK tubing from the sample syringe valve to the wash solvent sinker is loose, so the sample syringe eventually fills with air.

When running low-volume injections, air can prevent the sample syringe from drawing up sample correctly.

FIX or WORKAROUND

Tighten the connections on the PEEK union and purge the sample syringe at least 20 cycles.

ADDITIONAL INFORMATION

The issue occurs only when the solvent level of the bottle containing the Purge Solvent line is low enough for the PEEK union not to be submerged.