Preventive Maintenance and Troubleshooting
Chromatographic symptoms
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• The injector bracket is not aligned to the injection port. See the
appropriate link manual that describes the installation.
Syringe is worn or dirty
If the syringe looks dirty or the plunger is sticking, clean the syringe with an
appropriate solvent, or follow the syringe manufacturer’s cleaning instructions.
Sample volume is too low or too high
If the sample vials are not filled correctly, evaporation or contamination may
affect the analysis. The sample level should be approximately half of the
volume of the vial. See “Filling sample vials” on page 29.
Vial caps are loose
If you can turn the vial crimp caps by hand, they are too loose. Loose caps may
cause volatile samples to change concentrations over time. See “Crimp capping
sample vials” on page 30.
Sample is not stable
Some samples change with heat or ultraviolet light. Check the sample stability.
There are several ways to reduce changes to unstable samples:
• Use the injector fan to cool the sample waiting in the injector turret.
• Use the tray quadrants to cool the sample.
• Use amber sample vials.
• Store the samples in a protected environment.
Sample size varies
If the sample size varies, the syringe is probably not precise or the plunger is
worn. Variations may be due to syringes with removable type needles because
of dead volumes or needle-to-needle variation.
Air bubbles are in the needle
If air bubbles are in the needle, increase the run parameter that controls the
number of pumps. See “Number of sample pumps” on page 60.
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