Waters ACQUITY UPLC M-Class System Manual page 67

Suspected cause
Inconsistent retention times
4.3.2.3 Increasing or decreasing retention times
Suspected cause
Decreased flow rate
Incorrect solvent composition
Incorrect, degraded, or contaminated column
The system is not stabilized or chemically
equilibrated
Possible solution
Possible solution
Verify the flow rate setting.
See also:
Installation and Maintenance Guide on the
documentation CD.
Change the solvent composition, and then
autozero.
See also:
maintenance guide or the column care and use
manual on the documentation CD for
recommended equilibration times.
Note:
method, ensure that there is sufficient and
reproducible equilibration times between
injections.
November 26, 2019, 715003588 Revision C
Page 67
• Flush the column with 85% organic solvent.
• Clean or replace the column as described
in the appropriate column care and use
manual on the documentation CD.
• Rerun the analysis and observe whether
the retention times stabilize.
• Ensure cleanliness of the mobile phase.
The Universal NanoFlow Sprayer
• If contaminated, flush the column with 85%
organic solvent.
• Otherwise, clean or replace the column as
described in the appropriate columns care
and use manual on the documentation CD.
• Allow all system components (such as the
column and detector) sufficient time to
stabilize and chemically equilibrate.
• Ensure proper operating conditions for the
application (such as mobile phase, detector
settings, and detector type).
The component's overview and
When running an automated gradient