Chromatography Forum

I'm trying to account for standard weights, purity corrections, and dilutions separately into Empower (Empower 1 now - Empower 2 in about 2-3 months) instead of pre-calculating a corrected amount.
I've created the custom component fields, but can't work out how to use them. I think i should be able to either use a custom calculation to determine the corrected amount and then calibrate with that result instead of the amount or call upon the appropriate component fields in a custom calculation for the sample/peak. The problem is I can't figure out how to use a custom calcualtion for the X-value for the calibration curve or how to call on the appropriate std component value in a peak calcuation for a sample.
I know the solution to this should be relatively easy, but I can't figure it out for the life of me.
Thank you for your help,
sTeven

It sounds like you aren't using the labels in the sample set correctly which will cause a lot of issues with how Empower calculates the results.

For example labeling bracketing standards (in the label column) S0101 and S0201, and samples in between U0101, U0102, U0103, etc. Then in the Label Reference column of the calibration line entering S01* S02*, the following line quantitate, U01*.

Thanks LC_labrat for the help.
I think I'm using the labels correctly. They are at least in line with your example.

For this to work like I want it, I believe I need to be able to use a custom peak field for the X-axis of the calibration curve. According to Waters tech support, this is a feature in Empower 2, but Empower 1 is limited to the default Amount and Concentration only for the X-axis of the curve.

See if this helps clarify what i mean when referencing a component value in a sample calculation. If i create a component field called "StdPurity" and enter a number in for the component table for the standards, my peak calculation for a sample would be something like PeakAmount=Amount*StdPurity (I understand this isn't the correct way to account for a standard purity; this is just for an example) where the StdPurity value is pulled from the value entered in the component editor for the appropriate Standard. I don't know how to build the calculation so it goes to look for the component value (StdPurity in the case) entered for the standards used for the curve.

The quick work around for this that I have come up with now is to just enter the appropriate StdPurity for all the samples (unknowns) in the component editor. This may have to work until we have Empower 2 in place.
Thanks

I'm trying to account for standard weights, purity corrections, and dilutions separately into Empower (Empower 1 now - Empower 2 in about 2-3 months) instead of pre-calculating a corrected amount.
I've created the custom component fields, but can't work out how to use them. I think i should be able to either use a custom calculation to determine the corrected amount and then calibrate with that result instead of the amount or call upon the appropriate component fields in a custom calculation for the sample/peak. The problem is I can't figure out how to use a custom calcualtion for the X-value for the calibration curve or how to call on the appropriate std component value in a peak calcuation for a sample.
I know the solution to this should be relatively easy, but I can't figure it out for the life of me.
Thank you for your help,
sTeven

I enter Calibration Std concentrations instead of entering weights. I know this involves external calculations, but it's the easiest to do. You can also use Dilution and Sample Weight to use as divisor and multiplier respectively, for the Standard Sample type. They work the opposite way as they do for Unknowns and Controls. As for Component Custom Fields, you can use them in other Peak custom fields calculations, but this will probably require the user to select a custom field in the processing method for the X value, which the user may forget to do.

In Empower 2 and I think in Empower 1 you can select any custom field that has a "Real" data type in the x value column in the components tab in the processing method for any given component. I think it also still uses the Dilution and Sample Weight fields to adjust this amount, at least for standards.

make a custom field equal to area times the purity from the component editor. then set your Y in the processing method to the new custom field. That way you have incorporated the purity or anything else you want, into the calibration curve.

In this example you would have an extra edit amount tab for purity.