molecular weight and percentage recovery

[Muhammad Akbar Khan]

what is the relationshipe between percentage recovery and mocular weight of liquid in gas chromatography?
Does the percentage recovery effect the molecular weight of compounds?

Regards
Muhammad Akbar

[Don_Hilton]

There is no particular relationship between molecular weight and recovery. Now, if you have a particular set of experimental condtions, there may be a reason for a relationship. Please feel free to give some background on your question.

I am not sure about your question on recovery effecting molecuar weight. To change the molecuar weight of a compund, you have a chemical reaction going on...

[Muhammad Akbar Khan]

There is no particular relationship between molecular weight and recovery. Now, if you have a particular set of experimental condtions, there may be a reason for a relationship. Please feel free to give some background on your question.

I am not sure about your question on recovery effecting molecuar weight. To change the molecuar weight of a compund, you have a chemical reaction going on...

Thanks for replying, Actually, I injected three different liquid samples of GC Agilent 7890A, and calculated them by comparing with same reference liquid byGC calculator software. The molecular weight is the same for all three but %recovery is differenct of all.

Akbar

[Don_Hilton]

You would need to post some details to let us kow what you are doing? We dop not need to know what compunds you used, but we would need to know what calculations you used including how you knew concentrations going into the GC to what you measured coming out.

[Muhammad Akbar Khan]

Thannks Don,
Actually I want know the % recovery and molcular weight on GC. I am using here the Agilent 7890A GC, and calculations are done by software. If three different samples are injected and compare with the same reference fluid. My question is: how do we calculate the molecular weight by GC. Does molecular weight and % recovery have any relationship in GC calculations?

Best Regards
AKbar

[Peter Apps]

Thannks Don,
Actually I want know the % recovery and molcular weight on GC. I am using here the Agilent 7890A GC, and calculations are done by software. If three different samples are injected and compare with the same reference fluid. My question is: how do we calculate the molecular weight by GC. Does molecular weight and % recovery have any relationship in GC calculations?

Best Regards
AKbar

Since you already have three different recoveries for three samples with the same molecular weight, your own data should tell you that you cannot (under the conditions that you are using) calculate molecular weight from recovery.

The only way that you can get any measure of molecular weight by gas chromatography is by comparing the retention time for the unknown compound with a range of standards of compounds with the equivalent structure (homologs).

Peter

[Muhammad Akbar Khan]

Thanks a lot Peter,
Take care of yourself.

regards
Akbar