Thermo Scientific TRACE GC Ultra Maintenance And Troubleshooting Manual page 396

Chapter 19
Analytical Troubleshooting
Behavior Characteristics
Fronting
Ghost peaks
Ghost Broad ghost
peaks peaks
Irregular
Chair-shaped
shape
Negative
All
peaks
396
Cause
Column or detector
overloaded
Column temperature too
low
Stationary phase too thin
Contaminated carrier gas
Contamination from
laboratory glassware.
Decomposition of injected
sample
Dirty injection solution
Contaminated inlet or
pneumatics
Incomplete elution of
previous sample
Solvent flooding of column
Integrator wires reversed
Remedy
Decrease the injected amount
and/or analyte concentrations.
Increase the split ratio.
Increase the temperature.
Use a thicker-film column.
Replace the cylinder or replace
the filter.
Ensure the glassware is clean and
contamination-free.
Decrease the injection port
temperature.
Use the on-column injection
technique.
Carry out adequate clean-up of
sample prior to injection.
Remove the column and bake out
the inlet.
Use a high-quality septum.
Replace the split vent filter.
Install an in-line filter between
the pneumatics and the inlet.
Increase the final oven program
temperature or total run time.
Increase the column flow rate.
Increase the initial oven
temperature.
Reduce the injection volume
(OC).
Install a retention gap (OC).
Correct the connections.
Maintenance and Troubleshooting Manual
Peaks