Empower 2 Processing Issue

[dtherbert]

Hi everybody, I'm new to the forum. I found it while searching around and thought maybe I could find help here. Anyway...

We use Empower 2 (Build 2154). Normally we just use it for integration, after which we take the peak areas from the report and use them to calculate amounts by hand. We now want to use Empower to calculate amounts (about time, huh!). I took an old sample set we collected in 2010 (a simple one peak potency assay) and attempted to do this. At the time it was collected, a single method set was used which pointed to no processing method (empty field). We'd then process injections separately, with a different processing method being used for standard and unknown injections. No problem. By the way the order of collection was 3 standards, 2 unknowns, 2 standards (so bracketing).

So, taking this same sample set, I altered the sample to include all the labels, references, amounts, etc. that I figured I would need. I then created a method set for the standard injections pointing to the standard processing method and a method set for the unknown injections pointing to the unknown processing method. In the alter sample set window, I changed each injection's method set to its respective method (standard or unknown), and changed all injections to "don't process or report." I added lines for clear calibration, calibrate, and quantitate (all of which I believe have the correct references).

I then process the sample set. When I view my results, I have amount values for my standards (what I had entered in the "amounts" window), but I do NOT have any amount values for my unknowns. For the unknown injections, I get a peak code of "Q20." According to the built-in help, this means "Invalid curve, it has a flat slope." I don't think that's it exactly, though, I think it's just NOT using the calibration curve generated by the 5 standards. If I leave everything the same except change the method sets so they point to the same processing method (so all injections are processed with a single method), then amount values ARE generate for my unknowns.

So that's my problem, and it's quite vexing. Ideally I could just use a single processing method, but there are many times when the processing methods used for the standards and unknowns need to be different. At a previous job where I used Empower (not sure which version), I was able to use different processing methods and have it generate amounts with no problems at all, so I'm not sure what the issue is. Any ideas?

Thanks,

Dan

[aceto_81]

If I understand correctly, you use a processing method for your references, and another for your unkowns?
How would you transfer your calibration curve between your processing methods?
Why not use 1 method set, which contains 1 processing method for calibrating your references, followed by quantitating your unknowns?

Ace

[dtherbert]

If I understand correctly, you use a processing method for your references, and another for your unkowns?
How would you transfer your calibration curve between your processing methods?
Why not use 1 method set, which contains 1 processing method for calibrating your references, followed by quantitating your unknowns?

Ace

Thanks for the reply!

It sounds like you're saying I should just use a single method set (and therefore, a single processing method) for the entire sample set. While this will work for some samples we test, others require different processing methods for the standards and samples. This is usually because there is something in the sample (interfering peak, baseline issues, etc.) that prevent the injections from being integrated easily using a single processing method.

I was under the impression that if I used my standard injections to form a calibration for a specific component, I could quantitate that component using that calibration regardless of how the sample (unknown) injection was processed. Am I wrong? Perhaps I'm misremembering how this was accomplished at my old job.

Thanks!!

[MO Chemist]

The problem is that the calibration curves are associated with processing methods and not sample sets. Any injection that you want to quantitate with the curve needs to be processed with the processing method that has the curve "attached" to it. It is a pain but you have to try to create a processing method that works for both, if that is not possible then start looking into creating custom fields.
Good Luck.

[Karen01]

The problem is that the calibration curves are associated with processing methods and not sample sets. Any injection that you want to quantitate with the curve needs to be processed with the processing method that has the curve "attached" to it. It is a pain but you have to try to create a processing method that works for both, if that is not possible then start looking into creating custom fields.
Good Luck.

It's not really pain and that is wrong... it came and often does make life easier for me.

You need two processing method... The same injections can can be processed with as many methods as you want each saving their results separately...

I find that MUCH more flexible than the Agilent approach.

- Karen

[aquaregia]

Hey,

There is a workaround if you are allowed use batch processing with manual integration where you work.

1. Batch process sample set with one processing method/method set
2. Take results set into review
3. Manually change the results/samples you need to reintegrate. Just click quantitate (not integrate) to name peaks.
4. File -> Save each result and exit (just save modified results only).
5. Now Batch process that results set (click update first). Make sure to select 'use existing integration' tick box.

This will give a results set with just the 'new' manually integrated results which will have used the correct calibration curve. If you are on Empower FR5, you must have a processing method specified in your method set. This is not required in FR3.

Might work if you can do manual integration.

[Brockboy02]

Karen01,

Can you expand on your answer a bit? I am wondering how to do this as well. I know I did this years ago when i was working with Empower; nearly 10 years later and here i am again working with it (Empower 2). I love it, but forget so many of the little things.

[kevinkol]

I had come across a useful document for handling manually integrated results within result sets. It gives a little more detail around the solution aquaregia shared. I have uploaded it to google docs at the link below.

https://docs.google.com/open?id=0B7lk3J ... FdiWGFFZWs

Hope this helps,

Kevin

[Karen01]

Karen01,

Can you expand on your answer a bit? I am wondering how to do this as well. I know I did this years ago when i was working with Empower; nearly 10 years later and here i am again working with it (Empower 2). I love it, but forget so many of the little things.

I misread the question... but I do have to say if you can create a processing method that can validly integrate samples, it's hard to understand why it could not handle standards. which should be simpler.

In any case manual integration of the standards (or samples) is one way to go if you can't use the same integration method...

If you don't want (or are not allowed to) use manual integration, there is a way to use two integration methods...

You CAN use a standards only processing method for integration only, but then use the sample processing method for calibration... But you can't process then as a sample set but need to do it by injections or channels.

1) Select the standards (injections or channels-which makes sense in your case) and process them with the standards processing method but select "quantitate only"

2) Select the standard results generated and process those with the sample processing method but check "use existing integration" and set it to "calibrate only"

3) Then process the samples with that method , which should now have the current calibration attached, set to "quantitate only"

Sounds complicated but it can be done very quickly and easily

[Brockboy02]

Thanks Karen01 and aquaregia!

So, Karen01, your saying that if i do it by your method that i cannot achieve a Result Set and will only get a bunch of results?

Dan, were you able to get something that works for your original question?

This should help out quite a bit. I will give it a try and post here to let you know how it turns out.

[Karen01]

So, Karen01, your saying that if i do it by your method that i cannot achieve a Result Set and will only get a bunch of results?

As far as i know ... but it's not something I've ever needed to do.

One possibility might be to set up two processing methods in the sample set using two methods sets that differ only in processing method, one for standards and one for samples, then reprocess the result set with the Standards processing method using "Use existing integration" . That last is essentially aquaregia's Step 5.

-Karen