Calibration of GC machine with Acetaldehyde

Discussions about GC and other "gas phase" separation techniques.

4 posts Page 1 of 1
hello,
we measure the Acetaldehyde content in the PET Preforms.
we use the gc machine (agilent 6890) with FID,
for the GC calibration, we use the standard Acetaldehyde, purity 100%, concentration 1000 microgram/mL from Accustandard.


I am asking if it is possible to use one single point as a calibration or multiple points and how do we calibrate it.

thanks,
With a single point calibration, you first must prove that the detector responds linearly to your analyte coming out of your matrix. Once you feel comfortable that is the case, then I'm ok with doing single point calibration AS LONG AS your samples do not contain wildly different concentrations of the analyte. You need to use a standard that is of a similar concentration of your analyte. You are fortunate that you have chosen a flame detector because it is generally very linear over a very wide range of concentrations.

If you don't have a method, you need to get a book that will teach you about the analysis of solid materials using headspace sampling. I would recommend:

"Static Headspace Gas Chromatography. Theory and Practice" by Bruno Kolb and Leslie Ettre. Wiley-VCH is the publisher. There is a very good section in one of the chapters (4.1.3 in the first edition, 1997) that describes the critical things you have to consider to analyze solids like this.

There is much to consider when developing these types of methods. Too much to take on in this forum.
when using the single or multiple calibration points, i should have the same results, right?
and what should the difference be between the results of single and multiple point calibration?

can you provide me with information about companies that use the HS-GCFID Machine to test the Acetaldehyde in PET preforms.

thanks,
If you are properly calibrated, you should get the same answer no matter what. The answer is what it is.

You may only go to a single point If you have verified that your system is well behaved and that only running 1 point for the calibration standard is good enough for your purposes.

Most companies are not going to share their analysis conditions in the open like this forum. I suggest that you find some app notes by instrument manufacturers who have done it. It'll give you someplace to start. For example:

https://www.agilent.com/cs/library/appl ... 4355EN.pdf
4 posts Page 1 of 1

Who is online

In total there is 1 user online :: 0 registered, 0 hidden and 1 guest (based on users active over the past 5 minutes)
Most users ever online was 1117 on Mon Jan 31, 2022 2:50 pm

Users browsing this forum: No registered users and 1 guest

Latest Blog Posts from Separation Science

Separation Science offers free learning from the experts covering methods, applications, webinars, eSeminars, videos, tutorials for users of liquid chromatography, gas chromatography, mass spectrometry, sample preparation and related analytical techniques.

Subscribe to our eNewsletter with daily, weekly or monthly updates: Food & Beverage, Environmental, (Bio)Pharmaceutical, Bioclinical, Liquid Chromatography, Gas Chromatography and Mass Spectrometry.

Liquid Chromatography

Gas Chromatography

Mass Spectrometry