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- Information is available on:
-
- Entering Molecular Formulae
- _________________________________________________
-
- Note that if any read me files are supplied
- as part of this application, they may have
- more recent information than is contained
- in this file.
-
- IsoMass is © Chris Johnson, 1992
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-
- Entering Molecular Formulae
-
- The molecular formula is entered using chemical
- symbols in as near a natural manner as possible
- within the constraints of the standard WIMP
- interface. The program uses the normal chemical
- symbols for the elements. The case of the letters
- is important, eg chlorine must be Cl. The formula
- is entered in a single line and may contain up to
- 254 characters. The text in the icon will scroll
- as necessary when the length becomes too big for
- the display. As an example benzene would be
- entered as C6H6. The program checks through the
- formula for symbols it recognises, using the
- numbers as separators of the symbols. When only
- one atom of a particular element is present then
- it is essential to enter the figure one, eg
- methane would be entered as C1H4.
-
- This version of the program allows a maximum of
- 99 atoms of any particular element. There is also
- a limit on the overall number of atoms in the
- molecule, which depends upon the number of
- isotopes of each element, allowing up to 250
- different isotopic masses in total. Contact the
- author if you run into problems.
-
- When <RETURN> is pressed or the Calculate button
- is pressed, then the calculation is carried out,
- and the results are displayed, both as a listing
- of the data and as a bargraph.
-
- Clicking MENU leads to further options. The
- threshold intensity, below which peaks will be
- ignored, can be changed, as can the number of
- significant figures used to display the data. The
- data can be listed as fraction of total intensity,
- relative to the largest peak set to 100, or can be
- normalised relative to any value (see below).
-
- Normalise
- This leads to a dialogue box that allows you to
- set the intensity of a particular mass to any
- arbitrary value, typically 100. The intensities of
- all the other peaks are scaled accordingly. You
- may also choose to let the program simply set the
- largest peak to 100.
-
- Save data
- This leads to standard "saveas" dialogue boxes
- which allow the data to be saved either as a
- simple text file, or in MSPlotter format, which is
- an application for the production of high quality
- mass spec bargraphs. IsoMass supports RAM transfer
- for saving direct into applications such as Edit
- or MSPlotter.
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-