5
– Troubleshooting Guide
Thermo Scientific
Product Manual for CarboPac PA200 Columns
Page 26 of 37
065734-01
For Research Use Only. Not for use in diagnostic procedures.
5.
Troubleshooting Guide
The purpose of the Troubleshooting Guide is to help you solve operating problems that may arise
while using Dionex CarboPac columns. For more information on problems that originate with the
Ion Chromatograph (IC), refer to the Troubleshooting Guide in the appropriate operator’s manual.
Remember that some of the problems may be related to parts of your experimental protocol
(sample contamination, imprecision during sample transfer, etc.). The following text should help
you to locate and eliminate problems traceable to the carbohydrate hardware and chemistries. It
also provides a selection of cleanup and reconditioning procedures that have been found effective
by many users.
For assistance, contact Technical Support for Dionex Products. In the U.S., call 1-800-346-
6390. Outside the U.S., call the nearest Thermo Fisher Scientific office.
5.1
High Back Pressure
5.1.1
Finding the Source of High System Pressure
Column pressure, (after subtracting the system pressure) for the Dionex CarboPac PA200
Analytical Column should be close to the pressure listed in the QAR when using the test
chromatogram conditions.` If a Dionex CarboPac guard and analytical column are both installed,
column pressure will increase by approximately 20% over the pressure listed in the QAR for the
column. If the total system pressure is much higher than expected, it is advisable to determine
the cause of the high system pressure.
A.
Make sure that the pump is set to the correct eluent flow rate. Higher than recommended
eluent flow rates will cause higher pressure. If necessary, measure the pump flow rate
by collecting the DI H
2
O eluent for a specified time at operating pressure, and measure
the collected volume using an analytical balance. This data (weight/time) will give actual
flow rate.
B.
Determine which part of the system is causing the high pressure. High pressure could
be due to plugged or constricted tubing, an injection valve with a clogged port, a
column bed support clogged with particulates, or a clogged 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 200 psi. (unless a backpressure coil has been
installed between the pump outlet and the injection valve in which case, first
disconnect the eluent line from the pump to the backpressure coil). The pressure with
the eluent generator connected should be <400 psi. Continue adding system
components (backpressure coil (if present), injection valve, column(s), and detector)
one by one, while monitoring the system pressure. The pressure should increase by the
sum of the measured pressures of the individual guard and analytical columns (see
product QAR) when the CarboPac Guard and Analytical columns are connected.
C.
Measure the system back pressure by attaching a short piece of new 0.010” tubing in
place of the column.
NOTE
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