VINYL CHLORIDE different area with GC-FID

Hi

Are you using headspace for injection?

No, we unfortunately dont have headspace.. It is "normal" injection. 

Unfortunately I dont have practice of opening FID to clean it.. 

it looks like this: 

Then keep all flow of detector as it was early and ignite it..45: 450:45.

May be u need to ignite it from keypad..

I think found solution for that flame goes off!

I changed lit offset form standard 2.0 pA to 0.5 pA. During my analize signal value is 1.7-1.8 pA, so the GC thoughts the flame goes off and try to reignite. Now i inject solvent and full method goes without reignition! 

Great..

So do injection of VC with parameter we discussed earlier to see result..

okey im back!

I inject VC with parameters as you said and split 1:5 and the results are amazing! Every of 3 inj are same - area: 1)37,89; 2)38,24; 3)38,26 :) thank you so much.. could you please explain me how did you come up with that? This flow 30:300:30 - i understand, sample is longer in colum but what about inlet - how temperature can change that?

Im really thankful! 

I also see something that RT of peak is with every ijnection earlier, I mean:

1st: 2,186 min

2nd: 2,180min

3rd: 2,174min .. have you got any idea? 

okey im back!

I inject VC with parameters as you said and split 1:5 and the results are amazing! Every of 3 inj are same - area: 1)37,89; 2)38,24; 3)38,26 :) thank you so much.. could you please explain me how did you come up with that? This flow 30:300:30 - i understand, sample is longer in colum but what about inlet - how temperature can change that?

Im really thankful! 

I also see something that RT of peak is with every ijnection earlier, I mean:

1st: 2,186 min

2nd: 2,180min

3rd: 2,174min .. have you got any idea? 

Gr8...

Finally, we did it...

I was giving instruction to you by reading old document.

Even, so many times, we are developing methods as per our requirement.

From all those, experience, i guide you...

Thank you:)

Colud you tell anything about this changing RT? 

Big variation of RT or small variation..

Share column flow..

Share RT data to understand it..

as i said, it looks like it is always same difference (0,006 min): 

envilabeko said:

I also see something that RT of peak is with every ijnection earlier, I mean:

1st: 2,186 min

2nd: 2,180min

3rd: 2,174min .. have you got any idea? 

column flow: 2,97 ml/mim

column pressure: 2,8551 psi 

Do you have new septa with you.If yes, then change it..

Hold time of ramp oven temp may also be a reason.

But we will not go change any parameter.

Change septa and check column nut is tight from inlet n detector side.

May be small leak..

Onsite, you have to check these thing first then do injection again to see result..

Offsite, i can only suggest u..

Hello

Did you inject sample?