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issue with the MaxPlot in EMPower

Posted: Thu Apr 17, 2008 9:44 am
by lupetto
we observed something strange when extracting MaxPlot in empower (version 1154). when a drift in the baseline is present for a single wavelength (whole spectrum is recorded 200-400), the drift will no longer be present in the extracted maxplot. therefore it seems that MaxPlot is correcting the base line in some way.
we also observed that the purity results are different between a single wavelength (when extracted from spectrum) and maxplot (same processing method). it's probably related to the (unknown) correction that MaxPlot performs.

can anyone give us an indication?

in the chromatogram of the picture the black arrow is the maxplot extracted chromatogram. the red arrows indicate 2 impurities no longer visible when using the maxplot

[IMG]http://i30.tinypic.com/sq6n9h.jpg[/IMG]

Posted: Thu Apr 17, 2008 1:27 pm
by DR
Image

:: ^seeing if this works for me ::

OK - are you subtracting out a blank that also contains the baseline blips?

Posted: Thu Apr 17, 2008 1:35 pm
by lupetto
nope. we're not substracting the chromatogram from the blank run. is that what you mean?