Chromatography Forum

I am trying to take the peak area from the first standard injection and use it to compare the peak areas of my bracketing standards. Spec is +/- 15%

My original plan was to use this field:
ABS((CCalRef1[Area]/S0101.1.CCalRef1[Area]*100)-100)

That just returned a blank cell

Then I went this route:
CCalRef1[Area]/S0101.1.CCalRef1[Area]*100
I thought as long as my percent was 85-115% I would still be alright. This returned a blank cell

Then I tried:
Area/S0101.1.CCalRef1[Area]*100
Still nothing.

I cannot seem to get Empower to capture the area from the first of six standard injections.

Any suggestions

Many, many ways to skin this cat…

My preference is:

1. Label initial system suitability injections SS1.

2. Label bracketing injections SS2 .. SS9, or how ever many you need.

Custom fields:

1. SS1.%.%.AVE(Area) called SS1

2. SS2.%.%.AVE(Area) called SS2

Continue the above until you have the number that you need. These are peak type, real custom fields.

Create a final custom field called System_Suitability. This custom filed is a peak type, real field as well. This custom field looks like:

EQ(Label,"SS2")*((ABS(SS2/SS1)*100)-100) + EQ(Label,"SS3")*((ABS(SS3/SS1)*100)-100) …


The System_Suitability field allows you to create a table in a report with only sample information in addition to this column to show bracket results for all standards no matter if you have two or one hundred brackets.

Your custom fields are not working because the correct format of a summary function type custom field is X.Y.Z.Function(Parameter), where X= Label, Y=Injection, Z=Channel ID, Function= Mix, Max, Average, %RSD, etc, and Parameter= Area, Amount, another custom field, etc.

From your custom field you have the label and injection (though you are limiting to the first injection in all cases), and are using the parameter in place of the channel, which is why the field is not calculating. Furthermore, you have dropped out the Function from the custom field format.