- Carryover of polysorbate standard in test blank injections
- System flushed per recommendations in the Controlling Contamination document 715001307
- ACQUITY H-Class Bio
- ACQUITY ELS Detector
- ACQUITY PDA
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
- 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.