ACQUITY H-Class QSM retention time shift in SQT - WKB24158

SYMPTOMS

• All peaks during test injections and system precision do not occur in the 1-minute range
• Peaks are consistent in shape, height, and area but occur past 1 minute
• Using premix isocratic 90:10 H₂0/ACN yields normal, passing SQT parameters within 1-minute range
• Replacing GPVs does not alleviate the problem

ENVIRONMENT

• H-Class/Bio H-Class
• Empower 2

CAUSE

Degasser chambers have contamination or a clog.

FIX or WORKAROUND

Replace degasser chambers A and B.

ADDITIONAL INFORMATION

The system shows signs of salting and black mold in solvent lines. After cleaning, residual remained in the degasser chamber, causing issues.