Labelling peaks on Empower 2

[sankie]

Dear Guys,
I don't know how to label peaks in empower 2. can anybody help??

I am using whatman scx column in which the resolution will be changing all the time. so please tell me how to label peaks

Thanks in advance

[LC_labrat]

Were you able to figure this out? If not-in the processing method select the components tab you add the name of the peaks and identify them and identify them by the retention times.

[sankie]

Thanks for the reply,

But the problem is the retention time of the peaks will keep changing from the start of the column to the end.

So I cannot mention the exact timing of the peak.

Can you help in this issue??

[JGK]

Sounds like you have a spectacularly unstable method. I'd put the effort into stabilising things rather than figure out how to hit "moving goalposts" with peak IDs.

[sankie]

Thanks for the reply,

I think every Strong cationic exchange columns have problems with changing RTs. Is it true???

How do everyone label the peaks when using these columns???

[Kristof]

Each component in table has its own RT window. If peaks are not moving too far you can overlay all injections in the run and set RT and window just right enough to detect and label each component.

[sankie]

Dear Guys,
Thanks all for the reply.

I am not an expert in these things, so i cannot understand how to do it,

Can anyone explain me in detail please???


Thanks.

[aceto_81]

Or you can overlay all your windows, and use first, last, greatest height, ... to track your peak of interest

[EldredJonas]

Okay it sounds like you need to take some time to learn some of the fundamentals of the software.

Start here:
http://franklin.chem.colostate.edu/dive ... 1203rA.pdf

You'll need to become familiar with the peak matching rules in the components tab of your processing method. You can use the F1 key in any active window in Empower to access the applicable help topic. You'll find information there about what the various rules are.

Every chromatograph is different so your better off learning the software than trying to apply someone else's technique to your chromatography.

Good luck.

[sankie]

I am not using autosampler I am using manual injection using rheodyne injector valve

Please help me to find solution to this thing guys

[LC_labrat]

In order to label peaks the software requires you to "identify" the peak by selecting a retention time and then it will assign the label. This is done in the processing method components tab. You can then select the retention time window it can be as large or small as you choose, if you have multiple peaks in the same area you can additionally use the peak match drop down box to better identify the peaks via time (closest), area (greatest or least), height (greatest or least), if the order stays the same as it should, you can also add 1, 2, 3, or 4th peak. When reviewing the chromatograms you can select the options tab and and "show components" the software will include the RT and RT window so you can select and move them around as needed. The data processing is the same for both manual injection or an autosampler, you are still generating a chromatogram.

I highly suggest you read the manual that was provided.

[EldredJonas]

I second that notion: "I highly suggest you read the manual that was provided."

Once you learn how to use the basic software functionality to add components to your processing method you can use a feature called 'RT Reference' in the components tab as an aid to deal with RT shift.

First, you'll need a peak which appears in every chromatogram and is as isolated from the others as possible.

Next, you'll want to open the RT Window for this referenced peak large enough that it is labeled in every chromatogram (hence the need for it to be isolated from the others).

Lastly, assign this component as the 'RT Reference' for the others. As it shifts in RT, the component labels for all the other peaks will shift accordingly without having to assign any special Peak Match rules or adjust any RT Windows.

If you do not understand the basics then these instructions are probably very confusing to you. It would be wise to take the time to familiarize yourself with the manual. Or better yet, take an online course given by Waters. Here is one that would cost $100 that you can take on the web:

http://www.waters.com/waters/educationI ... =134718981

Good luck!