Thermo Scientific Dionex IonPac AG31, Product Manual

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5 – Troubleshooting
Thermo Scientific Product Manual for IonPac AS31 Columns Page 33 of 45
155007-01
For Research Use Only. Not for use in diagnostic procedures.
5.2.4 A Contaminated Guard or Analytical Column
A. Remove the Dionex IonPac Guard and Dionex IonPac Analytical Columns from the system.
B. Install a backpressure coil that generates approximately 1500 psi and continue to pump
eluent. If the background conductivity decreases, the column(s) is (are) the cause of the high
background conductivity.
To eliminate downtime caused by fouling, a guard column should be used. Clean or replace the
Dionex IonPac Guard Column at the first sign of column performance degradation. The columns
can be cleaned as instructed in Section 6.5.2 , “Column Cleanup Procedure”.
5.2.5 Contaminated Hardware
Eliminate the hardware as the source of the high background conductivity.
A.
Bypass the columns and the suppressor.
B. Install a backpressure coil that generates approximately 1,500 psi.
C. Pump deionized water with a specific resistance of 18.2 megohm-cm through the system.
D. The background conductivity should be less than 2 µS. If it is not, check the
detector/conductivity cell calibration by injecting deionized water directly into it. See the
appropriate manual for details.
5.2.6 A Contaminated Suppressor
If the above items have been checked and the problem persists, the Dionex Dynamically
Regenerated Suppressor or the Dionex Chemically Regenerated Suppressor is probably causing
the problem. For details on Dionex Dynamically Regenerated Suppressor operation, refer to the
Dionex Dynamically Regenerated Suppressor Product Manual (Document No. 031956). For
details on Dionex Chemically Regenerated Suppressor operation, refer to the Product Manual
(Document No. 031727).
a. Check the suppressor settings in the instrument method and look for any suppressor-related
errors in the audit trail.
b. Check the regenerant flow rate at the REGEN OUT port of the suppressor if operating in the
Auto Suppression External Water Mode.
c. Check the eluent flow rate.
d. Replace the regenerant water.
5.2.7 Contaminated Regenerant Water
If the suppressor is used with external water mode, especially in IC-MS or IC-MS/MS
applications, contaminated water can affect the system background and elevate conductivity and
background.
5.3 Inconsistent Retention Times
Inconsistent or shifting retention times could be due to one or several different factors. These
should be checked to determine the cause and address the issue.