Alliance 2695 gives shifting retention times - WKB207639

SYMPTOMS

• Shifting retention times

ENVIRONMENT

• Alliance HPLC System
• 2695 Separations Module

CAUSE

The sample is not totally dissolved in the mobile phase.

FIX or WORKAROUND

Dissolve the sample in the mobile phase and then filter.

ADDITIONAL INFORMATION

Samples are extracted with 100% methanol, but the mobile phase is 5% ACN in water. Some impurities are not dissolved in the mobile phase,which affects column efficiency.