3
Chromatographic Symptoms
Peak Boiling Point or Molecular Weight Discrimination Poor
For any inlet operating in split mode with any detector
For any inlet operating in splitless mode with any detector
54
If you have trouble with peak boiling point or molecular weight
discrimination (inlet discrimination), do the following:
• Check the inlet for contamination. Clean and change the
liner if necessary. Replace all inlet consumable parts. See the
Maintenance
manual.
• Adjust the inlet temperature.
• Run standards against a known method to determine
expected performance.
• Check liner type. Use a liner optimized for split analysis—one
that contains glass wool or other surface area packing to
allow complete sample vaporization.
• Increase the inlet temperature and verify that the insulation
cup is installed and contains insulation.
• Check column cut and installation into the inlet. See the
topic for the SS, MMI, PTV, and VI.
• Check the inlet for leaks. (See
• Check liner type. Use a liner optimized for splitless analysis
(deactivated, large volume).
• Verify that the oven starting temperature is less than the
solvent boiling point.
• Check column cut and installation into the inlet. See the
topic for the SS, MMI, PTV, and VI.
• Check that the solvent vapor volume does not exceed the
liner capacity.
• Check for appropriate purge delay time. (Liner
volume/column flow)
"Checking for
Leaks".)
Agilent 7890 Series Troubleshooting