Plugin: Type Analysis with GCxGC/Soft Ionization Data

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qtao
Posts: 122
Joined: October 7th, 2011, 10:16 am

Plugin: Type Analysis with GCxGC/Soft Ionization Data

Post by qtao » March 27th, 2018, 9:16 am

The Type Analysis plugins assist the analysis of compound groups in a complex mixture data acquired by two-dimensional chromatography coupled with soft ionization MS, such as Type Analysis by GCxGC/FI from JEOL.

Installation
The plugins require Version 2.6 or later.
  1. Download here: Type Analysis plugins
  2. Unzip using File Explorer or another application.
  3. Start GC Image.
  4. From the menu, select Tools > Manage Plugins...
  5. Import both SoftIonMS-TypeAnalysis and TypeAnalysisCLICFunc plugin folders.
Workflow
  1. For each group, create a single polygon area from SIC or CLIC.
  2. Specify the general formula in Group Name of the area. Note that the format of a general formula is elements followed by an expression in the curly brackets. For example:

    Code: Select all

    C{n}H{2*n+2}
  3. Tools->Type Analysis, and specify:
    • The range of the parameter
    • The constraint for identifying compounds
    For example, for n = 7 to 28, set the constraint to:

    Code: Select all

    ARelative(ExactMass("<group>"))>=5
    , where <group> will be replaced by a formula generated from the general formula specified in Group Name.
The results are reported as a compound table that lists the targeted formulas along with their apex retention times and total responses from molecular ions.

Constraints for Identifying Compounds
The plugins provide two special CLIC functions to make locating molecular ions easier:
  • FindBasePeak2(from, to) returns the base peak within the specified mass range.
  • FindBasePeak3("<list of masses>", tolerance) returns the base peak of the specified masses within a tolerance window.
Examples:

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(abs(FindBasePeak2(ExactMass("<group>")-1, 1000) - ExactMass("<group>"))<0.01) & Intensity("0-1000")>2000
  • The 1st part tests if the targeted mass exists as the rightmost largest peak.
  • The 2nd part tests if the TIC is below an absolute baseline (i.e. 2000).

Code: Select all

(abs(FindBasePeak3("{group}", 0.01) - ExactMass("<group>"))<0.01) & Intensity("0-1000")>2000
  • The 1st part tests if the targeted mass exists as the largest peak of its homologous group.
  • The 2nd part tests if the TIC is below an absolute baseline (i.e. 2000).

qtao
Posts: 122
Joined: October 7th, 2011, 10:16 am

Re: Plugin: Type Analysis with GCxGC/Soft Ionization Data

Post by qtao » March 29th, 2018, 10:44 am

See how to use the plugin in the following demo screencast:

Image

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