EmpowersBane wrote:
Hi and thanks for the further info.
Yes you can do this by labelling your 3 standards as S1 S2 and S3 then label your Batch samples as U1, U2 etc.
Change the formula to U%.%.(Response)/(S%.%..AVE(Response)) and change search order to Result Set Only.
You also must put the function Summarize Custom Fields as the last line in sample set, and ensure this line is set to Normal.
Then, process a sample set to generate a result set, where the values for each of the Batch samples will be calculated for this custom field.
Thanks you for your response @EmpowersBane !
It does work very well !
I will finally be able to get rid of my excel sheets...
lmh wrote:
I don't get this. Isn't it just a normal one-point internal standard calibration?
If you define the concentrations of A and B in the standard as both "1", and set up an internal standard calibration, one point, linear, forced to the origin, then the calibration curve is y=mx+c where c is zero and m is the slope, and x=1. Since y is the peak area ratio of the two chemicals, the calibration curve is y = (Area of A in std/Area of B in std).
The samples get read off this calibration curve, reading the point where y = (Area of A in sample/Area of B in sample) = (Area of A in std/Area of B in std) * x, where x is the concentration reported by the usual processing. That means that the concentration reported is indeed (Area of A in sample/Area of B in sample) divided by (Area of A in std/Area of B in std), which is what you wanted.
I tried to do this kind of calculation but I did not manage to get the expected results.
I'm not used to (first time) using the internal standard in EMPOWER, are there any subtleties that I missed ?
Something specific in the processing method maybe ?
To me, EMPOWER succeffully calculate the peak ratio (with the field Response and I saw it in the Review window when I display the field) but I can't manage to use the Reponse which I get from my sample and then divide it by the Reponse from my standard.