Empower Custom Field Query

[kingm3]

Hi,

I'm hoping someone can help me!!

I am running a simple assay as follows:

Std A
Sample X W1
Sample X W2
Std B

I can work out the amount for the samples - and other calculations.
I can also work out the average peak area for Std A and B.
But where my problem lies is with Normalised Area for the standards.
The procedure is looking for the % RSD of normalised area.
I have created a peak based custom field which is simply the peak area of standard A multiplied by the dilution (which is added in the run sample table) and I have called it NormalisedArea_A.
I have then done the same for standard B.
The results of these calculations are fine and correct.

The trouble starts when I try to calculate the % RSD. I cannot do this by component summary as there are two components.

I have tried to combine the custom field for the calculation - in other words apply the custom field for normalised area to both standards and when I do this I only get the correct answer for standard A but not B. I was hoping this would work, so I could use component summary to calculate the % RSD.

I then tried to create a result field based on the % RSD function in empower, however no matter what combination of the peak custom fields for NormalisedArea_A and NormalisedArea_B I use I cannot generated an answer.

It is possible that I am missing a bracket or a dot or something simple, but if anyone can shed some light on this I would be delighted.

Thanks,

Marion

[JJG]

Instead of creating custom fields for "NormalisedArea_A" and "NormalisedArea_B" you might try creating a field called "NormalisedArea" and just multiply the peak area by the dilution factor for anything. Then, in your report you can just report results for A and B standards.

If you paste the script then I could look at that too.

[kingm3]

Thanks for your help. Here's what I've done:

Peak Area Std A = 11880920 Dilution = 0.9970 (Normalised Area = 11845277)

Peak Area Std B = 11839171 Dilution = 0.99980 (Normalised Area = 11836803)

The fields I have created are:

Normalised Area_A = (S0101.1.(Area))*Dilution - I get the correct answer here.

Normalised Area_B = (S020B.1.(Area))*Dilution - I also get the correct answer here and can report them separately. But can't do %RSD

This morning I tried (S0.1.(Area))*Dilution and filtered the table to only report injections with labels S0* - I got no answers!

Then I tried Area*Dilution and still got no answers!

I'm not sure what I'm doing wrong. I understand that it would be better to calculate the value for all and then only report what I need. I'm not sure where I'm going wrong!

[kingm3]

OK, I restated Empower and reprocessed my sample set and I have generated the correct values.

Thank you so much for your help, I am currently working through all the QC analysis that use excel....so I will probably be back!