Need help with UV-spectra handling in chemstation (HPLC)

[vadzim]

Hi, sorry, if it already have been asked and answered, I tried to search and didn't find anything useful.
I use Chemstation Rev.B.04.03[16] and have 2 questions about the software:

1. I record UV-spectrum for whole chromatogram, but I'm unable to extract a chromatogram on any chosen wavelength, unless it was predefined in method settings, which is quite frustrating, since the data is obviously there. I'll clarify: I can see 3D plot and isoabsorbance plot, but I want a fully-featured chromatogram on a chosen wavelength, which I can integrate and get results from. I tried different approaches with 'load signal' function, but to no avail.

2. Is there any way to get a printed version of UV-spectra with assigned values of maxima and minima ?

Thank you in advance.

[lmh]

I'm really sorry, but I don't believe No. 1 is possible in Chemstation, although if anyone can contradict this I'd be really happy. I think it's a result of a philosophical decision by Agilent that they were collecting spectra, not necessarily all the time (to save file-size), and merely for confirmation of peak identity. As such, they didn't expect to reconstruct chromatograms from the spectral data, and didn't expect measured points to be available regularly at all times in the chromatogram, so they didn't expect it would always be possible (even though, in many people's cases, collecting spectra continously, or "every second spectrum", it would be a very sensible thing to be able to do).

[nimbi63]

Of course it's possible. One can do this with IsoPlot, but it's much easier to use a macro. On your B.04.03 DVD is a subdirectory \UCL (for User Contributed Library). Browse to \UCL\LC_UCL\Macros and open folder 4. Copy the macro file (LoadChro.mac) to your Chem32\Core directory. On the command line enter:
Macro LoadChro.mac, go

There will be a new menu item under File > Load that will allow you to select the signal wavelength/bandwidth and reference wl/bw.

[nimbi63]

Sorry, I only answered #1, for #2, browse to the same LC_UCL\Macros directory, open folder 5 and copy all EXCEPT the 'Readme.txt' and 'list' to Chem32\Core. On the command line enter: Macro Tools.Mac

OK the disclaimer, and there will magically appear a 'Tools' menu. Select Tools > Load Spectra Tools, then Tools > Spectra > Spectrum Min/Max Annotation.

[vadzim]

nimbi63,
I can't thank you enough. I really didn't even expect to find the answers, I thought at best I would get confirmation, that there is no way to do those things. Fortunately, you proved me wrong.
Thank you again.
On a side note, I don't understand why those features (at least extraction of chromatogram on a chosen wavelength) aren't basic.

[nimbi63]

You could always do this from IsoPlot. At the top left change the cursor from 'Quick View' to 'Signal', then you can set the wavelength and bandwidth. You can also check 'Reference' and set it's wavelength and bandwidth. Once you set these, click the 'Copy' button at the bottom to copy this to ChromReg.

To save the extracted file, click on the chromatogram window, then select View > Windows Functions > Save Window. When you later reload the data file, select View > Window Functions > Load Window.

[vadzim]

Yes, I see. And now that I know how to do it, it's not so difficult, not intuitive maybe, but not difficult. In Waters and Thermo software that feature is right on the surface, so I was looking for it in a wrong direction, I guess.

Anyway, here is another question: is it possible to make macros autostart at launch of Chemstation?

[nimbi63]

You can use 'User.mac' in Chem32\core. I use this to load macros, then call the macro as needed. I have a short user.mac to load the Tools macros, then initialize them:

Macro Tools.mac
SetHook "PreViewMenu", "Init_Tools"

If User.Mac exists, you can append lines. If it doesn't exist, create it in NotePad, but make sure it doesn't save as User.Mac.Txt.