IonPacAS9-SC
034656-06
Page 21 of 28
SECTION 6 - TROUBLESHOOTING GUIDE
The purpose of the Troubleshooting Guide is to help you solve operating problems that may arise while using IonPac AS9-SC
columns. For more information on problems that originate with the Ion Chromatograph (IC) or the suppressor refer to the
Troubleshooting Guide in the appropriate operator’s manual. If you cannot solve the problem on your own, call the DIONEX
Worldwide Office nearest you (see, DIONEX Worldwide Offices).
6.1
High Backpressure
6.1.1 Finding the Source of High System Pressure
Total system pressure when using the IonPac AG9-SC (4-mm) Guard and AS9-SC (4-mm) Analytical Columns at 1.0 mL/min
should also be less than 1,500 psi when using the test chromatogram conditions. Refer to Section 3.4, Eluent Preparation, to see
how solvent concentration can affect the column operating pressure. If the system pressure is higher than 2,000 psi, it is advisable
to determine the cause of the high system pressure. The system should be operated with a High-Pressure In-Line Filter (P/N
035331) which is positioned between the Gradient Pump pressure transducer and the injection valve. Make sure you have one
in place and that it is not contaminated.
A. Make sure that the pump is set to the correct eluent flow rate. Higher than recommended eluent flow rates will cause
higher pressure. Measure the pump flow rate if necessary with a stop watch and graduated cylinder.
B. Determine which part of the system is causing the high pressure. High pressure could be due to a plugged tubing or
tubing with collapsed walls, an injection valve with a clogged port, a column with particulates clogging the bed
support, a clogged High-Pressure In-Line Filter, the suppressor or the detector cell.
To determine which part of the chromatographic system is causing the problem, disconnect the pump eluent line from
the injection valve and turn the pump on. Watch the pressure; it should not exceed 50 psi. Continue adding system
components (injection valve, column(s), suppressor and detector) one by one, while monitoring the system pressure.
The pressure should increase up to a maximum of 1,500 psi when the column(s) are connected. The Anion
MicroMembrane Suppressor may add up to 100 psi. No other components should add more than 100 psi of pressure.
Refer to the appropriate manual for cleanup or replacement of the problem component.
6.1.2 Replacing Column Bed Support Assemblies
If the column inlet bed support is determined to be the cause of the high backpressure, it should be replaced. To change the inlet
bed support assembly, refer to the following instructions, using one of the two spare inlet bed support assemblies included in the
Ship Kit.
A. Disconnect the column from the system.
B. Using two open end wrenches, carefully unscrew the inlet (top) column fitting.
C. Turn the end fitting over and tap it against a benchtop or other hard, flat surface to remove the bed support and seal
assembly. If the bed support must be pried out of the end fitting, use a sharp pointed object such as a pair of tweezers,
but be careful that you
DO NOT SCRATCH THE WALLS OF THE END FITTING.
Discard the old bed support
assembly.
D. Place a new bed support assembly into the end fitting. Make sure that the end of the column tube is clean and free of
any particulate matter so that it will properly seal against the bed support assembly. Use the end of the column to
carefully start the bed support assembly into the end fitting.
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