Empower Custom field

Ol92

Hi,
I am looking for help with a custom calculation. 
It is a part of the formula that regarding a recovery: area std/area internal standard std (average of 3 injection)* area internal standard ctrl*area ctrl(average of 2 injection).
For the weight I have just create a custom field and it is correct.
Thanks in advace

Jovvor

Hey Ol92

You can easily create a custom field for your recovery.
The internal standard procedure is just a standard function within empower.
You set the internal standard within the components tab.

Enter the standard amounts and control value in your components tab in the run samples window.
Set the internal standard component amount to 1 for all standards and controls (if they all have the same volume added too them)

Create a custom field, for example Stnd_Recovery with the following settings

 Field type: Peak, Data type: Real (0.0), Calculated, Sample type: Controls Only (For example), Peak Type (Founds only)
Calculation: Amount/Control Value*100

That will give your recovery in % against the calibration curve for your control injections.

Hope you were looking for something like that.

lczenith

@Jovvor the CF "Control Value" is it a Default CF? If yes, what is the main Formula of this CF "Control Value"? Another question, if value of standard has a water % how could be included this water % with the Purity(vial)? Without do a manual calculation and insert the purity corrected with the water %. Thanks.

Jovvor

The Control Value is a default CF in empower. If you do inject Controls as function in your sample set, You can set a control value in your Component editor field. The Control Value is (probably) calculated as Control (Value) * Purity (seen as a 1.00000 value, 99.9% will be than converted as 0.999).

For your water content
First create a component custom field, name it for example Water_Content
You can than enter in your component editor the water content for your standard and controls

Second
Create a custom field, Peak type, Real, formula Amount*(100-Water_Content)/100
Set that custom field as your y-value in your proccessing mode in the components tab.
If i am right your amount in your samples will be calculated against the new calibration curve.

Remember to adjust your standard conformity custom field to incorporate the water content of your controls.
Else it will not take the water content in consideration.

lczenith

Hi @Jovvor thanks for the answer,

I trayed to do what you suggest, but when I change the `y -value` the results from standard and control was not calculated. So I am using this formula, but doesn’t work, may I am doing something wrong (please see the figure)?

Amount*([Purity (Vial)]*(100-Water_Content)/100)/100    

Purity(Vial) and Water_Content are located in Components Tab

Thanks.

Jovvor

Your Sample Type is set to Unknowns Only.
Change it to "All" and i guess it should work.

lczenith

I changed the Sample type for all, but still not working.

lczenith

@Jovvor, do you mean change the "Y-value" as indicated in the Figure? I don’t know why the CF don’t recognize the CF Water_Content. Thanks.