Waters 2489, Overview And Maintenance Manual

Page: 97 / 150

June 11, 2015, 715004752 Rev. A
Page 97
8. Pump a strong cleaning solvent, such as isopropanol, through the flow cell at
the recommended flow rate (optional).
If the flow cell is dirty, remove any other active detectors from the system, and
then pump 1% weak concentration acid solution (such as formic acid solution)
through the flow cell at the recommended flow rate.
9. Flush using HPLC-quality water at the recommended flow rate until the pH of the
effluent is neutral.
10. Reattach the column, and then resume pumping mobile phase.
Requirement: If the mobile phase is not miscible in water, first use an
intermediary solvent.
To reverse flush the flow cell:
If directly flushing the flow cell does not improve flow cell performance, reverse flush
it at the recommended flow rate.
1. Reverse the inlet and outlet tubing connections to the flow cell.
2. Flush the flow cell for approximately 15 minutes at the recommended flow rate.
Decreasing system pressure indicates the flow cell is clean.
3. If the flow cell remains dirty or blocked, remove and replace it.
4.4.2 Removing and cleaning the flow cell
If flushing the flow cell is not effective, follow the procedures to remove the flow cell
and inspect for dirty or broken windows or dirty gaskets. Clean and replace parts if
necessary.
Before removing the flow cell assembly, purge the flow cell with nitrogen, and allow it
to dry.
To purge the flow cell:
1. Connect the nitrogen supply line to the sample inlet, routing the sample line to
waste.
2. Purge the cell for 25 to 30 minutes at 103 to 138 kPa (1 to 1.4 bar, 15 to
20 psi).
3. Allow the flow cell to dry completely.
4. Disconnect the detector’s inlet and outlet tubing from the main column
connection and cap.
Warning:
To prevent injury, always wear eye protection and
gloves when handling strong acids or bases.