High %RSD; system readiness test failure - WKB285652

SYMPTOMS

• System readiness test failure
• One of the injections is either high or low, causing a high RSD
• Pump leak test and syringe leak test successful 
• No leaks from detector inlet or column outlet connection 

ENVIRONMENT

• ACQUITY UPLC Sample Manager
• ACQUITY RI detector

CAUSE

Bad column

FIX or WORKAROUND

1. Replace the column.
2. Purge and prime the system.
3. Equilibrate system.
4. Rerun system readiness.

ADDITIONAL INFORMATION

Customer did replace the column, but test still failed. I prepared fresh mobile phase and new standard. Checked for leaks. Test failed. 

Primed the syringe some more. Ran syringe leak test; test passed. Reran system readiness: test failed again. 

Replaced their column with one of my existing columns used for qualification; test successful. Reran the sample set to confirm results; system readiness passed again.