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Quantitation in Gas Chromatography

Posted: Wed Jul 02, 2008 6:21 am
by phuonghuynh
Thank-you very much for answering my question!

I understand what you said. I am using Agilent 7890A with flame ionisation detection.

My Boss said that we didn't calculate the result in HPLC on the basic of peak height ratio because of overloading peaks.

You know, in GC when you increase the concentration of the sample, the height of this peak will be increase proportionally but this is not true in HPLC. In HPLC when you increase the concentration of the sample to the limit, the height of this peak can't be increase anymore and the peak broden. So, we calculate the result in HPLC on the basic of peak area ratio.

In GC, if the sample is not purity there are a lot of ghost peaks. Some of them can be overlap the main peak and this makes the area of main peak increase. So, We have to calculate the result in GC on the basic of peak height ratio.

I didn't agree of his idea but i can't explain to him. I didn't also find any article which relates this problem.

Can you help me?

Anyways, thanks a lot!!! Smile

Posted: Tue Jul 29, 2008 8:56 pm
by s2008
Both overloading in HP LC analysis and low resolution in GC-FID analysis will bring inaccurate results. Calculating based on whether area of peak or height could not correct your results. In my opinion, you have to re-validate your method and then discuss how to calculate the results

Posted: Fri Aug 01, 2008 10:02 pm
by Ron
If you have a co-eluting compound that will affect the peak height as well as the peak area, so the answer is better chromatography if you need accurate quantitative results.