Loads2Chrom – identify modelled peaks from GC-MS datasets

About Loads2Chrom

Chemometric models (e.g. PARAFAC, PARAFAC2, MCR) can help to separate and purify overlapping peaks in GC-MS datasets into unique elution time and mass spectral profiles. However, software incompatibilities have prevented the modeled mass spectra from being easily compared to mass spectral databases. Recently, new software was developed to allow the identification of modeled peaks via the open-source chromatography and mass spectrometry software OpenChrom. On this page you can download software to convert model loadings of GC-MS peaks to *.mpl files, used by OpenChrom. In OpenChrom, the loadings can be converted to other formats or identified using NIST11 and NIST08.

 

Directions for identifying model loadings using OpenChrom are in:

 

 

Murphy, K. R.; Wenig, P.; Parcsi, G.; Skov, T.; Stuetz, R. M., Characterizing odorous emissions using new software for identifying peaks in chemometric models of gas chromatography–mass spectrometry datasets. Chemom. Intell. Lab. 2012, 118:41-50

 

To match modelled GC-MS peaks with spectra in NIST databases via OpenChrom, you will need:

·         One or more models (e.g. PARAFAC, PARAFAC2, MCR) of GC-MS peaks

·         OpenChrom  the open source chromatography software.  Get it here.

·         Either loads2chrom.m (runs with a licenced version of MATLAB) or loads2chrom_XX.zip (runs with the free MATLAB Compiler Runtime). This converts the model loadings from matrix format to the mpl format.

·         Access to a NIST mass spectral database

 

Download Loads2Chrom

 

This download contains:

1.       Loads2Chrom.m – MATLAB m-file that performs the conversion from matrix loadings to mpl format. Loadings are in data structures created in MATLAB or in the PLS_Toolbox for MATLAB.

2.       Loads2Chrom_86.zip  - Stand-alone executable for 32-bit (x86) Windows operating systems. Double-click on the icon to convert loadings in the OpenChromData folder from text files to mpl. Requires MATLAB Compiler Runtime 7.17 (MCR_R2012a_win32).

3.       Loads2Chrom_64.zip  - Stand-alone executable for 64-bit Windows operating systems. Double-click on the icon to convert loadings in the OpenChromData folder from text files to mpl. Requires MATLAB Compiler Runtime 7.17 (MCR_R2012a_win64).

4.       netCDFload.m - MATLAB m-file that loads netCDF files from different chromatographic software packages, and exports them as 2-D matrices. Requires MATLAB R2011a or later. With earlier MATLAB versions, use iCDF.

 

Related links:

ChromTools web site (to come)

The Odour Laboratory at the University of New South Wales, Sydney

OpenChrom web site

NIST mass spectral databases