Regarding gas chromatography
Thread Content
We are using the GC9800. We haven’t used it much recently; when we turned it on yesterday, we found that the FID would not ignite. We checked the pressures of hydrogen and oxygen, and they were normal. We can’t figure out what the problem is. Any experienced experts, please give us some advice
Check to see if any air duct is blocked The gas velocity also needs to be appropriate.
Reply to 1# ren_yanchao@126: 1. Increase the detector temperature. 2. Increase the hydrogen flow rate. Give it a try :sleepy:
It’s possible that the nozzle is blocked; when the detector temperature reaches the set value, use a micro-syringe to inject 1 uL of propane into the nozzle, let it burn for 10 minutes, and then try again.
Then check if there’s a problem with the ignition wire :)
(1) Leaks occur due to the high-voltage ignition electrode being too far away or having insufficient insulation resistance; adjust the distance between the electrodes to eliminate the leaks. (2) The low-voltage winding of the amplifier transformer is broken; replace the transformer. (3) The low-voltage ignition coil is damaged; replace the ignition coil. (4) The ratio of hydrogen to air is incorrect, and the nitrogen flow rate is too high; reduce the nitrogen flow rate or increase the hydrogen and air flow rates. (5) There is a leak in the hydrogen pipeline; fix the leak. (6) The nozzle is blocked; remove the blockage
Reply to 1# ren_yanchao@126: Check whether the ignition gun has power Is there a leak somewhere in front of the ion head? Is there enough hydrogen as well? Is there a problem with the ignition system – is the ignition coil oxidized or broken?
Increase the hydrogen pressure slightly and reduce the ignition air pressure; once the combustion is stable, gradually adjust the pressures back to their original values.
1. If there are two pipelines, check whether the one that is needed has nitrogen supplied to it. Hydrogen. Oxygen. 2. Increase the hydrogen pressure slightly, ignite, and then reduce the hydrogen pressure to an appropriate level. 3. If it’s a capillary column, check whether too much of it reaches the detector; pull it back a bit accordingly. 4. Is it because the activation time is short, hydrogen? The oxygen hasn’t arrived yet.
It won’t ignite. Increase the hydrogen flow a bit, and then gradually reduce it after it starts burning! That’s exactly what I did
Since the chromatograph was shut down for some time, it is normal for it to be difficult to ignite; the following methods can be used to initiate ignition: 1. After turning the device on, do not try to ignite it right away – wait at least 1 hour before attempting to do so； 2. The hydrogen flow rate can be increased slightly, but not beyond the limits specified in the instruction manual to avoid danger; meanwhile, reduce the nitrogen flow rate ； 3. Check whether nitrogen is flowing; do not focus on pressure, but rather on flow rate. If there is no flow or the flow rate is very low, it indicates that the nozzle is blocked, and it needs to be cleared using a stainless steel needle from a 5-microliter syringe ； 4. The method to check whether it has ignited or not is to use a lens test to see if there are any water droplets ； Check whether the level signal is rising ； Did you hear the roar?