3
Chromatographic Symptoms
Peaks Not Displayed/No Peaks
48
• If using an autosampler:
•
Ensure that there is sample in the vial.
•
Verify that the ALS plunger carriage is secured to the
syringe plunger.
•
Check that the syringe is installed correctly and draws
sample.
•
Verify that the turret/tray is loaded correctly and
injections are not from out-of-sequence vials.
•
Watch to see that the sample is pulled into the syringe.
• Verify the detector in use is assigned to a signal.
• Check the column for proper installation.
• Ensure that the column is not plugged. (See
Column
Flow".) Perform column maintenance.
• Check for leaks. (See
• Check the flow settings, then measure the actual detector
flows. (See
"To Measure a Detector
• Some samples change with heat or ultraviolet light. Check
sample stability.
• Check the sample level in the vial.
• If the sample is viscous, try the following:
•
Increase the viscosity delay time.
•
Dilute the sample in an appropriate low-viscosity solvent.
•
Turn the tower fan off.
•
For 7683B ALS, use the tray quadrants to warm the
sample. For 7693A ALS, use the vial heater (accessory
G4514A Bar Code Reader/Mixer/Heater) to warm the
sample vial.
If the problem is with the detector, see
"Checking for
Leaks".)
Flow".)
Table
3.
Agilent 7890 Series Troubleshooting
"To Measure a