Page 1 of 1
GC Quantifiaication using Chematation
Posted: Mon Aug 03, 2015 11:44 am
by ydna6969
Hi .
I have not used Chemstation in many years on HPLC (and know it was a nightmare to quantify impurities) but never on GC
How do you go about calculating results using an internal std ratio?
Also the version of Chemstation is B.03.01 SR1,, not an issue ?
thanks
Re: GC Quantifiaication using Chematation
Posted: Mon Aug 03, 2015 1:29 pm
by Consumer Products Guy
Chemstation is exactly the same for GC and for HPLC except for the one column for instrument setup on the first "Window". So same as the HPLC stuff was.
Re: GC Quantifiaication using Chematation
Posted: Tue Aug 04, 2015 6:11 am
by ydna6969
ok ,, eh ,, that doesn't really explain much though .
I can run a sequence but have not a clue how to quantify using internal std or peak area ratios.
Quantifying impurities on HPLC using chemstation ,, I get,, just !.. GC another can of worms !
Re: GC Quantifiaication using Chematation
Posted: Tue Aug 04, 2015 2:59 pm
by Consumer Products Guy
I can run a sequence but have not a clue how to quantify using internal std or peak area ratios.
We use a Sequence Summary Report to get results in Percent. We use either ESTD% or ISTD% as appropriate.
Re: GC Quantifiaication using Chematation
Posted: Wed Aug 05, 2015 10:36 am
by ydna6969
ok ,,what value do you put in for internal std (%ISTD)
how do you quantify or create calibration curves ,,, for a number of peaks ?
Re: GC Quantifiaication using Chematation
Posted: Wed Aug 05, 2015 4:12 pm
by Consumer Products Guy
ok ,,what value do you put in for internal std (%ISTD)
how do you quantify or create calibration curves ,,, for a number of peaks ?
I can't describe that in writing, would be too cumbersome. Even in person that would take me over an hour to teach someone. Go to Agilent web site and download PDF documents, or call 1-800-227-9770.
Re: GC Quantification using Chemstation
Posted: Thu Sep 03, 2015 6:27 pm
by KipDM
i will be using IS to mean Internal Standard.
for single point calibration just enter the concentration for the IS and Calibrator drug, this should set the ratio to properly quantitate for the rest of the batch (this works best if you are using a dueterated analog of the drug as your IS).
you will need to set this for each individual drug (or peak).
i cannot remember the specific options from the menu you have to go through to get to these settings because i have not had to use them for a while and don't use this software at all with my current employer.
if you are using a multi-point curve to establish linearity for each batch i am not sure how to set this up, as we used to use GCMS for only single point calibration where the linearity had previously been established by QA/QC.
hope some of that helped,
KDM