Hi guys,

Trying to integrate the peak for Ethylene in my GC.

I was told that to be accurate I should use different concentrations of calibration gas for that, but I only have one concentration (100ppb).

Is that a way to integrate accurately using only one concentration?

Also, does anyone have a very didactic material showing how to integrate a peak on openlab??

Please help,

Thanks.

By "integrate accurately using only one concentration," I assume you mean 'accurately calculate' using one concentration. Most USP methods use one external standard for calculation, and the method is generally validated for accuracy between 80 - 120%. Other organizations use calibration curves for low concentration contaminants.

I successfully validated methods for low concentrations using a single external standard formulated at the top of the analyte specification limit. Results accuracy depends upon methodology, analyte, and matrix.

For Oxygen determination in a Nitrogen filled container, I use a certified 0.2% Oxygen in Nitrogen gas cylinder to calibrate our MicroGC and calculate results. The 0.2% is the upper specification limit.

What OpenLab software do you have; e.g., CDS, Chemstation, EZchrom?

For OpenLab CDS EZchrom software, there are ways to use sequence calculation. Here is a link to the concepts and workflow manual:

(Links removed by moderator as security cannot be verified)I use "Single Run" option. Using this way, input a Calibration Factor in the method for automated calculations.

For OpenLab CDS Chemstation, here is a link to the concepts and workflow manual:

https://www.agilent.com/cs/library/usermanuals/public/CDS_CS-concepts.pdf

(Link removed by moderator as security cannot be verified)I hope I answered your questions. The above brief sketch works for my lab. The manuals give much more detail, print screens, and possibly better options for your lab.

Good Luck and Chromatograph On!