Carryover of standard sample in blank injections on ACQUITY H-Class Bio - WKB23379

SYMPTOMS

• Carryover of polysorbate standard in test blank injections
• System flushed per recommendations in the Controlling Contamination document 715001307

ENVIRONMENT

• ACQUITY H-Class Bio
• ACQUITY ELS Detector
• ACQUITY PDA

CAUSE

Likely void volume in column outlet and flow cell inlet fittings and tubing interconnections

• Systematic contamination was observed (after all the lines were changed) as carryover was finally flushed out.

FIX or WORKAROUND

1. Replumb the PDA with a new PEEK line from the column outlet to the PDA flow cell inlet.
   • Any tubing after the injector that is not properly seated could retain contamination or void and be a source of carryover.

ADDITIONAL INFORMATION