Waters ACQUITY UPLC Operator's, Overview And Maintenance Manual page 62

10. Reattach the column.
11. Resume pumping mobile phase.
If the mobile phase is not miscible in water, first flush with an
Tip:
intermediary solvent.
Performing a system, acid-cleansing flush
Caution:
system, acid-cleansing flush. Instead, call Waters Technical Service.
General system contamination can spread to the flow cell. If the system
becomes contaminated, perform a system, acid-cleansing flush, which cleans
the solvent manager, sample manager, and flow cell.
To prepare the solvent
1. Prepare a mixture of 50:50 (v/v) methanol/water:
a. Measure 500 mL of water in a graduated cylinder.
b. In a separate graduated cylinder, measure 500 mL of methanol.
c. Add methanol to water, and mix for 5 minutes.
2. Prepare a mixture of 30:70 (v/v) phosphoric acid/water:
a. Measure 700 mL of water in a graduated cylinder.
b. In a separate graduated cylinder, measure 300 mL of phosphoric
acid.
c. Add phosphoric acid to water, and mix for 5 minutes.
3. Fill a 1-L mobile phase reservoir with 100% water.
4. Fill a 1-L mobile phase reservoir with 100% isopropanol.
The cleaning procedure takes approximately 6 hours, once the solvents
are prepared.
50
If you are running a mass spectrometer, do not perform the