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Posted: Thu Feb 16, 2006 7:45 pm
by Consumer Products Guy
Tom is correct (as usual). Specifically, what I'd do (since I'm the one who states the "standard" integrator is easier for me) is:
set Integrator OFF at time = 0
set Integrator ON at time = 6.5 minutes
set Integrator OFF at time = 10 minutes
click OK
click Integrate (Agilent always needed a "OK and Integrate" button there)
if these changes look better, re-save the Method.M.
Personally, under Graphics, Signal Options, I'd also set the USE RANGES from about -20 to about 50, and re-save the Method.M, to make visualization easier.

And, Tom, I also am not able to upload a picture; I'm way more computer-dumb than the bored board observers may think. For Letsdoit, I copied his link and that's how I viewed his picture. For example, for a truck board, I tried to upload, then finally stated if you want to see photos of my carb installation, go to www.xxxxxxx.com

Sorry for the figure

Posted: Thu Feb 16, 2006 8:11 pm
by letsdoit
I dont understand what you mean by lock the integration..
Could you please elaborate it a bit.
Thanks
Image

What you need to do is to "lock out" integration around that big negative dip near the beginning of the chromatogram.

Posted: Fri Feb 17, 2006 6:21 am
by Consumer Products Guy
I believe Tom means ignore early peaks or data points, start counting peaks later in the run, similar to what I posted.

Posted: Fri Feb 17, 2006 6:22 am
by Consumer Products Guy
And this is easier than it seems. Make a change, reintegrate, and if it helps, Save the Method.

Posted: Fri Feb 17, 2006 8:56 am
by Tim
The link to your chromatogram doesn't appear to work and doesn't come up with anything if you paste into the Address bar.

However, from what you and Tom have said, to stop ChemStation from integrating round the solvent front, Add Integration Off at 0 and Integration On at whatever time after your solvent front. This won't affect the way ChemStation integrates the rest of the chromatogram.

If you still get the baseline appearing to come from the dip (even though it isn't drawn in), you will still need to add a Valley-to-Baseline On event close to the start of the run.

Posted: Fri Feb 17, 2006 5:04 pm
by tom jupille
And, Tom, I also am not able to upload a picture; I'm way more computer-dumb than the bored board observers may think. For Letsdoit, I copied his link and that's how I viewed his picture. For example, for a truck board, I tried to upload, then finally stated if you want to see photos of my carb installation, go to www.xxxxxxx.com
The problem is actually my fault. The program that runs the Forum understands only three graphics file formats: .gif, .jpg, and .png. The chromatogram in question was a .bmp file (different format), so the only way to view it was via the link as you described. I now realize that my original sticky post was ambiguous (I've edited it to clear up the confusion).

I have to keep reminding myself of the old adage "To err is human, to really f*** up requires a computer!" :wink: