This Information Applies To: Agilent GC Systems with flame ionization detector (FID)
Issue
Baking out the flame ionization detector at high temperatures can remove sample contaminants that have deposited on the detector surfaces.
- Ferrule, no hole 10/pk (p/n 5190-4054)
- Column nut, any of the following:
- Column nut, universal (p/n 5181-8830)
- Blanking plug, finger-tight style (p/n 5020-8294)
- Finger-tight column nut (p/n 5020-8292)
- Column nut, collared, self-tightening, inlet/detector (p/n G3440-81011)
- FID/NPD capillary adapter (Adaptable FID style only) (p/n 19244-80610)
Steps to follow
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Load the normal GC method and wait for the GC to become ready.
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Note the value of the FID signal output for comparison with value after the bake-out.
- 7890 GC Systems: On the instrument front control panel, press [Front Det] or [Back Det] then scroll to output.
- 7820A GC Systems: On the Agilent software keypad (remote controller), click [Front Det] or [Back Det] then scroll to output.
- 8890 GC Systems: On the touch screen or the browser interface, go to Home > Status listing > +Add. Select the detector’s output from the drop-down list, then select Add.
- 8860 GC Systems: On the browser interface, go to Home > Status listing > +Add. Select the detector’s output from the drop-down list, then select Add.
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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:
- To cool the oven and detector, load the GC maintenance method
- Remove the column from the detector
- Plug the detector connection with the column nut and the no-hole ferrule. For adaptable FID style configurations, make sure that the capillary adapter is installed.
- Turn off the carrier gas and remove the column from the GC inlet.
Warning: If using hydrogen as a carrier gas, turn off the hydrogen supply and remove the column to prevent an oven explosion.
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Load the normal operating flows. If the column has not been removed from GC inlet, maintain inert carrier gas flow through the column.
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Light the FID flame.
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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.
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Set the oven temperature to 250 or 25 °C above the normal maximum operating temperature. Do not exceed the inlet temperature.
- If the column is still installed, set the inlet temperature to 250 or 25 °C above the normal maximum operating temperature. Do not exceed column maximum temperature. To bake out the GC inlet see How to Bake-out the Split/Splitless Inlet (S/SL) on Agilent GC Systems .
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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):
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Allow the instrument to cool and reinstall the column if appropriate.
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Load the normal analytical method and allow the system to equilibrate.
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Check the FID output value. It should be lower than the first reading.
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