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Thermo Fisher Scientific

Analytes Eluting Later Than Expected


Retention times longer than expected for target analytes


All ICs for al applications


  1. Check that the flow rate is what is expected.
  2. If eluent is prepared manually, double-check preparation or reagents used for preparation, including water.
  3. If system has RFIC-EG, have servicer go through steps to verify whether EG module/electronics are working properly, which should determine whether the EGC must be replaced.
  4. Review whether a new column has been installed recently and the age of the outgoing column (chromatography may have become less accurate over time).
  5. Make sure the same column types are being used for direct comparison.


Generally, either the flow rate or the eluent strength has diminished. In some cases, a new column will appear to push retention of analytes later, when, in reality, an older column has likely lost the capacity to do so.


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