Loss Of Resolution For Early Eluting Peaks; Spurious Peaks; No Peaks, Poor Peak Area Reproducibility Or Too Small Peak Areas - Thermo Scientific CarboPac PA200 Product Manual

5 – Troubleshooting Guide
5.3.3

Loss of Resolution for early eluting peaks

If poor resolution or efficiency is observed for early eluting peaks compared to the later eluting
peaks, check the following:
A. Improper eluent concentration may be the problem if retention time is less than expected.
B. Column overloading may be the problem. Reduce the amount of sample ions being
C. Sluggish operation of the injection valve may be the problem due to partially plugged
Improperly swept out volumes anywhere in the system prior to the guard and analytical/capillary columns may be the
problem. Swap components, one at a time, in the system prior to the analytical/capillary column and test for early
eluting peak resolution after every system change.
5.3.4

Spurious Peaks

A. The columns may be contaminated. If the samples contain an appreciable level of
!
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.
NOTE
B. The injection valve may need maintenance. When an injection valve is actuated, the
5.3.5

No Peaks, Poor Peak Area Reproducibility or too Small Peak Areas

A. Check the position and filling levels of sample vials in the auto sampler.
B. Check injector needle-height setting.
C. Check if there is any bubble trapped in the sample syringe of the auto sampler.
D. Check each line of the schedule for proper injector parameters. Revert to full loop and
E. Service the injection valve (check for leaks, Tefzel fragments, or sediments inside the
Thermo Scientific
065734-01
Check the flow rate of the pump, as pump flow rate will affect the eluent concentration
in an RFIC-EG system. Ensure the Eluent Generator is set to the correct eluent
concentration.
injected onto the analytical/capillary column by either diluting the sample or injecting a
smaller volume onto the column.
port faces. Refer to the valve manual for instructions.
polyvalent ions and the column is used with a weak eluent system, the retention times
for the analytes will then decrease and spurious, inefficient (broad) peaks may show up
at unexpected times. Clean the column as indicated in "Column Care".
possibility of creating a baseline disturbance exists. This baseline upset can show up as
a peak of varying size and shape. This will occur when the injection valve needs to be
cleaned or re-torqued (see injection valve manual). Check to see that there are no
restrictions in the tubing connected to the valve. Also check the valve port faces for
blockage and replace them if necessary. Refer to the Valve Manual for troubleshooting
and service procedures. Small baseline disturbances at the beginning or at the end of the
chromatogram can be overlooked as long as they do not interfere with the quantification
of the peaks of interest.
column appropriate sample loop size.
valve).
Product Manual for CarboPac PA200 Columns
For Research Use Only. Not for use in diagnostic procedures.
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