This Information Applies To: Agilent GC Systems with flame ionization detector (FID)
Baking out the flame ionization detector at high temperatures can remove sample contaminants that have deposited on the detector surfaces.
Steps to follow
Load the normal GC method and wait for the GC to become ready.
Note the value of the FID signal output for comparison with value after the bake-out.
Determine if you need to remove the column. The detector bake-out temperature is 350 to 375 °C. If this bake out temperature exceeds the column manufacturer's upper temperature limit, remove the column otherwise, jump directly to step 4:
Warning: If using hydrogen as a carrier gas, turn off the hydrogen supply and remove the column to prevent an oven explosion.
Load the normal operating flows. If the column has not been removed from GC inlet, maintain inert carrier gas flow through the column.
Light the FID flame.
Set the temperature zones to the bake-out temperatures:
Caution: Do not exceed the column manufacturer's recommended temperature, as it will damage the column. If the bake-out temperature exceeds the recommended temperature, remove the column and turn off the inlet gas flows.
Set the detector temperature to 350 to 375 °C, or 25 °C higher than the normal operating temperature.
Set the oven temperature to 250 or 25 °C above the normal maximum operating temperature. Do not exceed the inlet temperature.
Hold at temperature for 30 minutes or until the baseline settles at a lower value. The baseline will typically rise, then fall to a final value lower than the initial baseline (Figure 1):
Allow the instrument to cool and reinstall the column if appropriate.
Load the normal analytical method and allow the system to equilibrate.
Check the FID output value. It should be lower than the first reading.
Learn how to effectively operate your Agilent GC Detector: