7.11
Section 7
TroubleshooTing
Pinnacle Operators Manual
Pickering Laboratories Inc.
PROCEDURES
TO REMOVE SILICA DEPOSITS FROM REACTOR
Silica deposits are too hard to remove. Replace the reactor(s). Carefully clean or replace other components in
the flow path. You must remove all the silica before the system will work again. This will probably entail major
repair.
TO REMOVE MINERAL DEPOSITS IN THE REACTOR FROM HARD WATER
The Pickering pumps and most (but not all) HPLC pumps will tolerate this. Columns and autosamplers probably
will not tolerate this.
1. Remove analytical column
2. Start HPLC pump at < 0.5 mL/min (100% H2O).
3. Replace both post-column reagents with deionized water. Run post-column pumps for 5–10 min.
4. Stop post-column pumps. Replace deionized water with 20% nitric acid and run post-column pumps for
10–15 min.
5. Reverse the order of washing with water and then replace with the post-column reagents.
TO REMOVE GREASE DEPOSITS
Grease deposits can be dissolved by replacing column and guard with a union and pumping methanol through
the HPLC and post-column systems. Stronger solvents such as acetone, methylene chloride, or tetrahydrofuran
(THF) may be needed. If methylene chloride is used, be certain to flush the system thoroughly with methanol
before and after because methylene chloride is not miscible with water.
IF REAGENT BACKFLOWS ONTO COLUMN
This procedure usually works but may not work every time.
1. Shut down the Pinnacle PCX.
2. Flush both columns with regenerant. Use a very slow flow rate so that the back pressure does not exceed
2000 psi. Collect effluent in a beaker.
3. Keep flushing until the pressure drops. Keep raising the flow rate until the pressure is normal at 0.40 mL/min
and 55C.
4. Run a chromatogram to check for resolution.
IF ORGANIC SOLVENT IS ON CATION-EXCHANGE COLUMN
Even small amounts of common organic solvents like Methanol or Acetonitrile will cause cation-excahnge resin
to swell leading to high column pressure. Always make sure all organic solvent are removed from HPLC system
and all the connecting lines before installing cation-exchange column. Small amounts of organic solvents from
HPLC system could be removed by the procedure below. Guard column and analytical column should be flushed
separately.
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