7-2
Ver.1.36
SYMPTOM
CAUSE
SOLUTION/CHECK POINTS
Polar compounds not eluting
from the system
Degraded column
Replace column or check again using Ultra
ALLOY column (UA5) to see how this changes.
Tars deposited in the ITF
needle
Clean or replace it.
Increase ITF temperature.
Poor deactivation of pyrolysis
tube
Inorganic compounds may have deposited.
Clean or replace it.
Poor reproducibility of
pyrograms
Gas leak
See section 7.3 for details.
Improper pyrolysis
temperature
Set temperature to proper pyrolysis
temperature.
(Set furnace 50ºC higher than end temperature
observed in EGA thermogram.)
Sample amount or shape not
uniform
Try to use same amount of sample and uniform
sample shape.
Depending on samples, good reproducibility may not be obtained. If the problem
persists, check the system with polystyrene standard.
Furnace and ITF
temperatures do not reach set
temperatures
Heaters not turned on
Turn heater on.
Power breaker open
Re-set the main breaker on the back of the
controller.
Broken heater
Repair needed
Temperature controller
malfunctioning
Repair needed
No cooling gas
Cooling gas not supplied
Check cooling gas supply valve and pressure.
Malfunctioning of EM valve in
the rear of controller
Repair needed
Cooling in the range of 800 to
1050 ºC
If furnace temperature is 800ºC or higher, the
cooling gas does not flow; the furnace is
allowed to cool itself. Once the furnace is below
800 ºC, the cooling gas is turned ON.
Cooling gas tube is plugged.
Connect the cooling gas directly to the cooling
gas inlet port of the furnace to confirm the tube
is open. Repair needed if the gas does not
flow.
Septum residues remain in
the septum area when
replacing septum
Adhesion caused by the
thermal decomposition of
rubber
Remove the residues using a solvent such as
hexane.
Use Frontier Labs' surface treated septum to
reduce the adhesion of the septum.
Increase baseline at high
temperature region under
programmed heating (high
background)
Bleeding due to deterioration
of column stationary phase
Perform solvent cleaning. This may help reduce
bleeding. Run 1 mL of acetone through the
column, then connect it to GC and turn carrier
gas ON. Set the oven temperature to 40ºC and
hold for 30 min then raise the temperature at
10ºC /min until dry.
If column i
s not Frontier Labs’ Ultra ALLOY
column, contact column manufacturer.
