Chromatography Forum

I was performing Lab course for cracking of n-hexane. The reactor outlet stream goes to GC which gives peaks. I only know the calculated reactor inlet flowrate of n-hexane. Does any body know how to calculate conversion from GC peaks?

In general, the areas of those peaks will be proportional to the quantities of materials in the mixture entering the GC. Depending on the GC detector, the response to a specific compund may vary. (Thus it is important to know the response of the detector for each compound formed of you have a system where you can assume the same response for each.)

If you just want the conversion of hexane to something else then as long as the hexane flow is the same (or you correct for changing flows) then just use the hexane peak area from the GC (not area%). If you need to quantify other hydrocarbons (unsubstituted) then you can approximate by using the area of the hexane peak (the raw material with 0% conversion) as long as you are using FID detection. If you want more accuracy then either get some standards as suggested or there are response factors in the standard BS EN 27941. You woul still need to know the identities of the peaks though.