Chromatography Forum

I am having trouble with empower and our go-to empower analytical worker is on maternity leave and very busy (as you can imagine) and hasn't responded to me so i thought i would post the question here.

I am very new to learning the software and i am processing peaks but when i go through the amounts under review in the review set tab they are 10-fold greater than the actual amount. for example the theoretical concentration tested is 21uM...the amount reported for the individual peaks is 210.324uM but in the summary report it is reported as 21.0324uM. the peaks pass the %RSD and %CV based on the amount i entered while altering the samples, despite the amount listed in the multi sample summary report is 21uM for the theoretical and the calculated is 210uM so i want to believe that the correct value is the 21uM. i went through my processing method and didnt find anywhere i could manipulate the amount but again i am new to the software so i could have very well missed it.

i would like some help so i can fix my data from having a 1%dev on my summary report with values being reported as 140uM and 1400uM in the individual report

This sounds really weird, is it possible to post an example of your report?

Ace

I don't know if you have checked this:
- Are you using some kind fo internal standard and if yes - have you checked component table if you have right amounts in sample and standards?
- Have you checked "dilution" and/or "amount" or similar fields in you sample set?

we are not using a internal standard and the error occurs in the "Amount" column in comparison to the "Calc. Value" the amount is off by a decimal point and it occurs in all our projects. for the time being we have removed the column and replaced it with concentration which reports the value similar to "calc. value" but is there a feature to add or remove a dilution because i have not found one in the column properties and im assuming that is the problem that there is a 10-fold dilution programmed somewhere.

maybe you have a mistake in one of your calculation parameters?
have you checked all of them.
did you do a manual excel curve as well and have you checked the functions between excel and empower?

its calculating correctly with %CV and %RE's around 1-15% for passing peaks because it is calculating using the "Calc. Value". The problem is that when I look at the peaks after processing under the "Amount" column for example they are reporting concentrations of 21000uM instead of 2100uM as listed in the "calc. value" column. The reports show a %CV and %RE of ~0.1% because the theoretical concentration (the value i entered as the standard amount) was 2100uM. That is were the problem is because if the "Amount" shown by empower is really 21000uM but the entered amount for that standard was 2100uM then the %error should be much greater than 0.1%. all the standards and QCs are the same way... if the prepared concentration i entered was 85.7uM the "amount" column reads something like 874.643uM the "Calc. Amount" column reads 87.464uM and the % error is below 5%

Have you checked the settings in the processing method?
what do you use as fit-model (linear or linear thru 0) and what about the x (or y)-axxis unit (amount or conc).
maybe the thing is introduced somewhere there (see the help on when using which one)

Also, have you checked the inputs in your sample set table? make all columns visible and check them all. Maybe there is a factor of 10 hidden somewhere (dilution column)?

Have you checked the settings in the processing method?
what do you use as fit-model (linear or linear thru 0) and what about the x (or y)-axxis unit (amount or conc).
maybe the thing is introduced somewhere there (see the help on when using which one)

Also, have you checked the inputs in your sample set table? make all columns visible and check them all. Maybe there is a factor of 10 hidden somewhere (dilution column)?

This is the first thing that came to my mind. Would your injection volumes happen to be 10 µL?

yes, my injection volumes are 10uL

yes, my injection volumes are 10uL

Are you entering amounts or concentrations for you standards in the component editor? if you're adding concentrations for example, but have your y-axis set to "amount" in the processing method, then you'll get a 10 fold difference in your answer b/c it will take into effect your injection volume.

I checked my processing method the y-value=area and the x-value= concentration and we enter concentration into the editor

I checked my processing method the y-value=area and the x-value= concentration and we enter concentration into the editor

So it makes sense that your "Amount" is coming out 10x higher than, because for amount, the concentration will be multiplied by your injection volume. If it's concentration you want, you might have to unhide the concentration row in the summary table.

which is what we did....i was just really confused but that makes complete sense and I'm very thankful for your help! Our lead empower person is gone and this difference has been a nightmare for me basically with empower 101 training.

thanks again!!!!