Chromatography Forum

Dear Colleagues,
apologizing for frequently wondering but I first faced this problem.
GC produces a signal without turning on the FID Detector!? Please look at the attached photo.





After turning on the detector and then conditioning the column while the instrument waiting for injection, the baseline appeared as in the attached image.

for considering my type of sample is highly concentrated organic Solvents.
I assume that the carbon is scaled at the jet but I want to ensure from experts before I commence.

If the detector is off it could simple be background noise in the electronics.

What is the scale of the signal?

If the absolute signal is in the single digits then just noise, if it is in hundreds or thousands then something may be shorting out in the detector.

If the detector is off it could simple be background noise in the electronics.

What is the scale of the signal?

If the absolute signal is in the single digits then just noise, if it is in hundreds or thousands then something may be shorting out in the detector.

Yes, the value is small approximately 0.1 pA.

If the detector is off it could simple be background noise in the electronics.

What is the scale of the signal?

If the absolute signal is in the single digits then just noise, if it is in hundreds or thousands then something may be shorting out in the detector.

Yes, the value is small approximately 0.1 pA.

What you guys mean by "detector is off" ?
No flame or electrometer switched off ?
How high is the signal when electrometer is off ?

Edit:
Just checked my FID. Signal is zero when the flame is off (no matter whether electrometer is on or off).

If the detector is off it could simple be background noise in the electronics.

What is the scale of the signal?

If the absolute signal is in the single digits then just noise, if it is in hundreds or thousands then something may be shorting out in the detector.

Yes, the value is small approximately 0.1 pA.

What you guys mean by "detector is off" ?
No flame or electrometer switched off ?
How high is the signal when electrometer is off ?

Edit:
Just checked my FID. Signal is zero when the flame is off (no matter whether electrometer is on or off).

Dear, the detector is off, I mean the flame is off.

It won't hurt if you thoroughly clean your detector. Plastic insulators should not be touched with bare fingers to avoid salt deposits.

BTW - I assume you have the signal in question with hot FID. When FID is cold small amount of moisture may cause elevated signal.