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ChromaTOF - calibration curve - for beginners

Posted: Thu Oct 27, 2011 11:21 am
by ingesfomsgaard
We have purchased a LECO Pegasus instrument and as the first thing we wish to setup a quantitative method. We have received a detailed written explanation on the steps to follow from the application chemist, as seen below. In II.3 we are supposed to open a dropdown menu and click "Add standard". But the most of the functions in the dropdown menu are dimmed (including "Add standard") and cannot be clicked. We want the instrument to do quantifications NOW. Can anybody help us? We have experience in ABSciex and Agilent chromatography/MS. Apparently there is something we miss when setting up ChromaTOF for quantification. We have run several samples and see the chromatogrammes and the spectra etc. But we cannot make the standard curve.

This is the explanation from the application chemist:
How to create a calibration:
I. First data processing
1. One of a higher standard has to be processed with a “normal” processing method (Baseline, Peak find, Library search and Calculation of Area and Hight)
2. In the processed Sample (Acquired sample) enter in the Peaktable the column “Group” (right mouse button -> Column -> Group.
3. Sort the Peaktable by Name (right mouse button -> sort)
4. In everyline where you find one of your compound enter a “g” in the column “Group”
5. Check the Name and the spectra. If it´s not the right one open the “Hit table”
6. Is the compound in the Hit table, select the whole line, right mouse button -> selct hit. Now it is entered in the Peak table.

II. Create a Calibration
1. Go to the Calibration and create a new one (right mouse button -> new) To rename again right mouse button and “rename”
2. Open the window a) Calibration Table b) Standard Table c) Calibration Curve d) Spectra and e)Chromatogram
3. In the Calibration Table add the processed standard (right mouse -> add standard)
4. Enter again the column “Group” and sort by Group.
5. Delete all the other compounds, which are not relevant for the Calibration. (Minus button on the top)
6. Enter the right quantification mass or masses
7. Enter the concentration in the last column (the column is named by the sample name)
8. To calculate enter again right mouse button -> calculate standard.
9. Add the other unprocessed concentration levels. Right mouse -> add standard.
10. Enter the conentrations in the cloumns. You can use the “fill option” to do this. Select the column -> right mouse -> fill.
11. Calculate the standards (right mouse -> calculate standard)
12. After the color changed from green, red to black, the calibration is calculated.

III. Quantify a sample
1. Create a new processing method
2. Only select “ apply calibration” and add the calibration in the processing method
3. Now select the sample and process it.

Re: ChromaTOF - calibration curve - for beginners

Posted: Fri Oct 28, 2011 12:24 am
by Don_Hilton
Sounds familiar - I have come to this point before and my problem was that I did not have a method open, Just the calibration table panes. (I've built many calibration curves in ChromaTOF.)

Be sure that you have created a calibration table - you have to right click in the files pane and select the option to create the new calibration. Give the calibration table a name other than "new." Name it somethign meaningful - it saves on trouble later.

So, be sure on those steps. If you are still having a problem, let us know which version of ChromaTOF you are using.

Let us know how things work for you.

Re: ChromaTOF - calibration curve - for beginners

Posted: Fri Oct 28, 2011 7:10 am
by ingesfomsgaard
Thanks a lot! That was the problem. We had a Teamviewer demonstration by the application chemist half an hour ago and she showed the same thing. But we could not read that from the explanation we had yesterday.