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CS2 analysis by FPD

Posted: Mon Feb 04, 2019 4:56 pm
by Chemiger
Hi
I will be using an FPD detector to analyse samples of petroleum ether for Sulfur species. I read that the FPD gives a quadratic response. I was planning on running different concentrations of sulfur as Carbon Disulfide to see if the method I have is linear. Now I dont know if that would work. Does anyone know if the FPD detector would produce a suitable calibration or will i need to look at using an internal standard as a means of calculating Sulfur content ?
Thanks,
Chemiger

Re: CS2 analysis by FPD

Posted: Tue Feb 05, 2019 8:17 am
by Peter Apps
FPDs typically give you the option of taking the square root of the signal automatically, which linearizes the response. The operator's manual or the manufacturer's web site will tell you what you need to know about settings.

Peter

Re: CS2 analysis by FPD

Posted: Tue Feb 05, 2019 8:27 am
by Chemiger
Thanks Peter will look at the manual today.

Re: CS2 analysis by FPD

Posted: Wed Feb 06, 2019 2:13 am
by AICMM
The FPD is quite non-linear. You can plot curves but you need multiple levels of standard to accurately develop the curve. The other difficulty is that you may saturate the photomultiplier which will define the upper end of the curve for you.

Likewise, I think you are assuming it is equimolar and it is not. Response is compound specific so you cannot just apply CS2 response factor to other components. Therefore, I am not sure what you are trying to accomplish with the use of an internal standard.

Best regards,

AICMM