Poor reproducibility after replacing 2695 sample needle - WKB397

SYMPTOMS

Inconsistent injection volumes and poor reproducibility after a new needle was installed on 2695.

ENVIRONMENT

• Alliance HPLC System
• 2695 Separations Module

CAUSE

Bubble in Syringe.

This can be an issue when purging with 100% water after needle replacement.

FIX or WORKAROUND

1. Thoroughly purge injector 20 times with 50/50 Methanol/Water, and then finally with 100% Methanol .
2. Loosen the syringe screw at the bottom and manually purge to remove air bubbles.

ADDITIONAL INFORMATION