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SOFTWARE FOR MASS SPECTROMETRY
Over time, members of TARC with an interest in mass spectrometry have written computer programs that perform a variety of helpful calculations to further their own research interests. The program, IsoPatrn, determines isotope cluster patterns for both simple and tandem mass spectra. ISOMABS6 provides a variety of information including simple isotope cluster patterns, the accurate masses of non-covalently bonded cluster ions, atom enrichment levels, and the possible formulae of ions with a specific mass-to-charge ratio. TARC provides these programs gratis as downloads as explained below.
IsoPatrn
IsoPatrn determines the isotope cluster pattern of an ion in eithger a simple or tandem mass spectrum (MSn for n up to 4). The ion may contain any of the elements in the Periodic Table with stable isotopes. Six user-defined elements may also be introduced. Calculation of isotope patterns for product ion, precursor ion, or neutral loss mass spectra is supported.
The code, written for Windows-based personal computers in Microsoft Visual C++, employs the "classical" polynomial expansion algorithm and uses 80-bit floating point math routines to improve accuracy for very large molecules. IsoPatrn requires a 32-bit or a 64-bit operating system, Windows 98 or later. There are no large memory or disk space requirements.
IsoPatrn provides regular Windows features including HTML-style help, hard-copy output, and the ability to save the results to simple text files, the data in which are comma-delimited for ease of importing into a spreadsheet program. The most recent edition of IsoPatrn is Version 2.13. This version contains several features not included in previous editions. These include the ability to list the individual isotopologue components that make up the higher mass peaks of the isotope clusters in simple, product ion (MS2 to MS4), and neutral loss spectra. In these cases the data can be plotted, producing a spectrum at a resolution specified by the user. This spectrum can be exported (saved) in graphical format as an enhanced metafile, which can be imported easily and directly into word processor, spreadsheet, and presentation applications.
IsoPatrn is provided in compressed or "zipped" form in a package of 465 kB. Download IsoPatrn.
ISOMABS6
The ISOMABS6 program will calculate ISOtopic Masses and ABundanceS found in mass spectral isotope patterns, as well as give possible formulae and classify ions as even- or odd-electron for a given m/z value.
Essentially all compounds containing elements with two or more natural or user-enriched isotopes exhibit mass spectra having isotope cluster ions. Most of the ISOMABS6 program is designed to assist with understanding and dealing with the features arising from these clusters of ions. This program provides the following suite of features:
- calculation of isotope cluster patterns in single-stage MS from naturally-occurring species,
- calculation of isotope patterns from ions having user-specified isotopic enrichment,
- calculation of isotopic enrichment levels from the experimental mass spectrum of a compound enriched in a specific element,
- calculation of accurate mass-to-charge ratios and isotope patterns of noncovalently bonded cluster ions,
- calculation of all possible formulae for ions within a specific range of m/z ratios, which can be very helpful in interpreting fragmentation patterns in a mass spectrum,
- correction of experimental peak intensities for ions having intense [A-1] ions,
- display current isotopic data for any of the 84 stable elements.
The most recent edition of ISOMABS6, Version 6.0, was written for Windows-based personal computers using Microsoft Visual C++. It requires a 32-bit or a 64-bit operating system, Windows 98 or later. There are no large memory or disk space requirements. The latest version provides regular Windows features including HTML-style help, hard-copy output, and the ability to save the results to simple text files, the data in which are comma-delimited for ease of importing into spreadsheet programs. Other features include: (1) the ability to include all of the 84 stable elements in almost any of the calculations, (2) provision for up to six user-defined elements in most of the calculations, (3) the ability to estimate the enrichment of all the isotopes of an element with up to four isotopes.
ISOMABS6 is provided in compressed or "zipped" form in a package of 430 kB. Download ISOMABS6.