EzChrom Elite Method Report Totals Q

[Revan]

Hi,
I have a question. I have created the method report in EzChrom Elite 3.3. I added fields for retention time, peak id, peak area, ESTD Conc and Totals.
Everything seems to be in order, but the totals under ESTD are about 60-70% and not 100% as I excpected. I suspect its connected to the calibration curve.

Anyone has any idea which field I should add to see a column like this?

H2 46%
CO 41%
CH4 3%
CO2 10%
Totals 100%

Instead of current:

ESTD Conc
H2 33%
CO 29%
CH4 3%
CO2 7%
Totals 72%

So basically % of gas in injected sample, because I am not sure what those current values mean.

[ydna6969]

Hi ,

Yeah possibly calib curve.
Make sure you have clear calibration as run type before processing sequence then check calib curve for ext standards
My experience on Version 4.4 and 4.6 ,Ezchrom does some weird and wonderful things for quantifying results for no apparent reason

[Revan]

Thanks for reply. I have checked calibration and everything seems to be ok, I have curve for each gas and it was uploaded into method. I am doing single runs, so I only need the method report be set up properly. Still getting those weird results - by weird I mean that its probably taking the point from curve responsible for 100% hydrogen then reading the value, then taking value from my single run, calculating the ESTD % and then putting it into report, thats why I am probably seeing those weird totals of 60-75%

[HPLCaddict]

Still getting those weird results - by weird I mean that its probably taking the point from curve responsible for 100% hydrogen then reading the value, then taking value from my single run, calculating the ESTD % and then putting it into report, thats why I am probably seeing those weird totals of 60-75%

Yes, of course it is doing it like this. That's how calibration via external standard works. Why should this be weird?

Look at your values:
ESTD Conc
H2 33%
CO 29%
CH4 3%
CO2 7%
Totals 72%

Of course the totals are 72%. That's simple algebra.

What exactly are you doing and which results do you want? What are your external standards? How do you calibrate (which levels did you define in the peak table?)?

[Revan]

Yeah I suspected as much. My question is related to those values.
So basically I calibrated those gases by using the pure gas and setting the proper concentration via gas itself and dilution with argon to get curve that has points like 15%, 30%, 50%, 100%

Now I am doing measurements of gas mixture where I am supposed to check the levels of H2, CO, CO2 and CH4, due to ESTD values I am not getting the 100% in Totals, thats obvious, but is it possible to either calculate or select value in EzChrom so I can have total counts from chromatogram as a 100% and the peaks that were found as x%?

Edit:
I have checked the other variations of reports and Area% is not viable, due to the area of hydrogen peak, which is like 97% of all peaks, but what about Normalization, I saw H2 there as about 50% and Totals is 100%. It is viable to use?

[Revan]

bump

[varossf]

Well the results for ESTD are correct, but select Norm Amount then your ESTD percentages will be normalized to 100%

[Revan]

Ok, thanks