12 July 2013

474. MS data, part I: Exporting data as csv from wsearch32, and generating MS assignments using Matt Monroe's molecular weight calculator

NOTE: I've heard rumours about problems with wsearch on Windows 7 Home, and on Windows 8. I've heard reports of it working on Windows 7 Professional. Curiously, it works just fine on linux under wine.

This post is written with two particular students in mind. I could put this in a pdf and email it, but why not share with the wider world since other people may encounter the same issues?

See here for part II: http://verahill.blogspot.com.au/2013/07/480-ms-data-part-ii-plotting-and.html

1. Exporting data from wsearch32
To install wsearch32 under wine, see here: http://verahill.blogspot.com.au/2013/01/321-wsearch32-in-wine.html

In order to export data from wsearch so that you can plot it in e.g. gnuplot, octave, origin or excel, do the following:

Open a spectrum (chromatogram) and pick a slice, then click on the M/I icon in the bottom right:

 Pick Save As

 And save as e.g. csv (comma separated file)


2. Using formula finder in Matthew Monroe's Molecular Weight Calculator
To install the molecular weight calculator in wine, see here: http://verahill.blogspot.com.au/2012/09/matt-monroes-molecular-weight.html

Open the molecular weight calculator and go to edit abbreviations.

 Add an abbreviation for MeO. We'll call it Methx, and it has a charge of -1:
 Hit OK to save the changes.

 Go to formula finder:

We'll be looking for Ga, NO3, MeOH, O, H, MeO. Then click on Formula Finder Options:
 Limit the charge to 1:
 And search:

You can do fancier stuff, e.g. searching directly for the m/z and bound the search to min/max amounts of different elements:
 As shown here:

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