GPV (Composition Accuracy) test failure with propylparaben mobile phase in 2695/Alliance - WKB297303

SYMPTOMS

• GPV test failure with A/B/C and A/B/D lower than 9.5 %

ENVIRONMENT

• 2690/5
• Alliance

CAUSE

• Check valve failure
• C/D ratio higher than 1.60

FIX or WORKAROUND

1. Inspect Diag for a C/D ratio lower than 1.60.
2. Sonicate the check valve in 100% water and then 100% methanol.
3. If the C/D value is still high, replace the check valve.
   • 700000254 - Ruby Standard Check Valve
   • 700002399 - Ceramic Check Valve

ADDITIONAL INFORMATION

During GPV test, pressure will be constant. Delta psi will be within a 2.5% limit of system pressure.