Broad tailing peaks with malic acid on a new column at startup - WKB203481

SYMPTOMS

• Broad tailing peaks visible with malic acid and malic acid isomers

ENVIRONMENT

• Peak shape problems
• Reverse phase
• Metal interactions
• Mobile phase
• Non-specific binding

CAUSE

Malic acid interacts with metals in the flow path and column.

FIX or WORKAROUND

Add 1-ppm citric acid to the mobile phase.

ADDITIONAL INFORMATION

The citric acid will preferentially bind to free metals and exposed surfaces to reduce interactions with the malic acid; peak shape will improve.