Chromatography Forum

Hi guys
I'm using GC-2010 Fid (Shimadzu). At the beginning there was no problem in air flow, but now (after 30-40 runs) now the FID ignition is failed . I checked the system and found some problem in air flow rate. i.e the the air flow rate set value (400 mL/min) can't be maintained. I checked the gas pressure, likage, Fid port but I failed to solve this problem. My set value for Hydrogen flow= 40 mL/min, For make up gas= 30 mL/min . I'm working with glycerol derivatives. Column temperature = 40 Degree, FID temp= 300
Any suggestion is highly appreciated.
Thanks,

Hi guys
I'm using GC-2010 Fid (Shimadzu). At the beginning there was no problem in air flow, but now (after 30-40 runs) now the FID ignition is failed . I checked the system and found some problem in air flow rate. i.e the the air flow rate set value (400 mL/min) can't be maintained. I checked the gas pressure, likage, Fid port but I failed to solve this problem. My set value for Hydrogen flow= 40 mL/min, For make up gas= 30 mL/min . I'm working with glycerol derivatives. Column temperature = 40 Degree, FID temp= 300
Any suggestion is highly appreciated.
Thanks,

I would start with cleaning FID jet. Then would try to ignite flame with more forgiving flows eg. air 150, hydrogen 20 and make up 5 or 10.

The air to an FID does not go through the jet, so cleaning that will not make any difference to the air flow.

Can you confirm that the pressure in the air line that goes to the back of the GC is within the specification required by the instrument ?

Is the air flow consistently low or does it fluctuate ?, and how are you measuring it ?

Peter

The air to an FID does not go through the jet, so cleaning that will not make any difference to the air flow.

(...)

but even partially clogged jet will affect hydrogen flow making ignition impossible (in the worst instance).

Diagnosing problems with FID without cleaning jet is not a good idea for beginners.

That's why I adviced to try to ignite FID with clean, non obstructed jet, and than changing flows of gases diagnose further.

Hi Malaya,

Is there a progress with diagnosing FID problem?

Feedback is very important to us from educational point of view.

Hi
There is no progress in FID.
I cleaned the jet and checked the air leakage and pressure ( air pressure is 400 kpa) but no improvement in situation. Then After this
I decreased the hydrogen flow rate from 40 ml/min to 35 ml/min and air flow rate from 400 ml/min to 90 ml/min just to check. Now the flame is stable. But I'm wondering is it the correct proportion of hydrogen to air?
Thanks

Hi
(...)
I decreased the hydrogen flow rate from 40 ml/min to 35 ml/min and air flow rate from 400 ml/min to 90 ml/min just to check. Now the flame is stable. But I'm wondering is it the correct proportion of hydrogen to air?
Thanks

Probably it's fuel rich.
Is the column properly installed in FID ?

Hi
i have Shimadzu GC-2010 Plus, i met with same problem, flame is not working.
My set values; Hydrogen; 40 ml/min, air flow; 400 ml/min, make up gas; 30 ml/min, column temp:35 C , FID temp;250 C and i am working with VOC.

Firstly i tried to solve the problem with increasing the Hydrogen from 40 ml/min to 80 ml/min. flame worked just one time then it wasnt working

Second solution method: as it was written i decreased the Hydrogen from 40ml/min to 35 ml/min and air flow from 400ml/min to 95ml/min it didnt worked.

after a few tries; the problem is written on software like that

(110f) GC Error
Det#4 ignition failed [E4206]

Also on software i cant stand flame in ON position. it started to be OFF position automatically.

i am waiting your comments, thanks so much

Whenever there is an ignition or flame stability problem with an FID you have to measure the flow rates of the hydrogen, air and make-up gas using an independent flow meter - not the flow meters that are built into the GC. Until you have confirmed that the flows are correct there is no point in trying anything else.

Changing gas flows arbitraily just to get the flame to light is poor practise and will adversely affect the performance of the detector.

Peter

If the jet is not sealing correctley into the base of the FID, you will be able to measure the correct flows but will not be able to ignite the flame, as the hydrogen will come up around the side of the jet instead of through the jet.

Gasman

If the jet is not sealing correctley into the base of the FID, you will be able to measure the correct flows but will not be able to ignite the flame, as the hydrogen will come up around the side of the jet instead of through the jet.

Gasman

Very true - but there is not much point in pulling the FID apart to check the jet seal unless you know that the problem is not due to incorrect flows.

Peter

The jet hasnt been removed any more, may this problem be caused by air?? we changed air two days ago then only one sample was analyzed then GC was closed. After closing GC, i opened it next day but i came across this problem. i havent still found a solution.

Thanks Peter for your commet, i will measure air flow as much as possible

You also need to measure the hydrogen flow, and the makeup gas if you use it.

Peter

today FID jet is removed carefully, and it is left in a methanol to clean it, but it broke down like as shown on photos

http://imageshack.us/photo/my-images/83 ... 11001.jpg/

http://imageshack.us/photo/my-images/71 ... 011003.jpg

is it possible to broken in methanol by itself??? or why is it broken ?? when it is removed, it is completely OK. may it be broken while GC is running ?

Also on software i cant stand flame in ON position. it started to be OFF position automatically.

i am waiting your comments, thanks so much

Regarding this, try to remove the autoignite check on software and to ignite it directly from the instrument, bypassing the software (DET>ignite on the small display). I found it to be a lot faster than waiting an ignition through GCSolution, initially i had the same problem with the flame in OFF position even when it was clearly burning.
Tell me how it goes then.

Regarding the flame stability problem, i have a Shimadzu GC-2010 plus ECD/FID with 2 injectors and i didn't have any problems with the flows yet, but i'm using it only since september. Hope you'll solve this problem because it could be useful to me as well in the future.

is it possible to broken in methanol by itself??? or why is it broken ?? when it is removed, it is completely OK. may it be broken while GC is running ?

I'm new to this instrument but it is clearly impossible that either methanol or running it on the instrument could make it break. It was either defective or badly installed (screws turned too much etc, but again i'm new to it and never installed/removed it yet, nor i know how it is mounted)