What’s New in GC/ID Version 2.0?
A New and Improved Deconvolution Algorithm
Other deconvolution algorithms utilize only the spectral centroid data with a vague consideration of what a chromatographic peak shape should realistically be. Centroid data is typically nominal mass and the non-linear nature of the centroiding operation “filters” valuable underlying details in the mass spectrum making accurate deconvolution difficult. While the approach can work reasonably well, its main drawback is the tendency to “overfit” the data and produce a large number of incorrect spectra. This places a huge burden on the analyst who must evaluate the many “false” spectra that may be produced.
Cerno’s approach, TrueChrom MX™, uses the full profile mode data that is calibrated for both accurate mass (easily within +/- 20 mDa) and spectral accuracy (typically 99%) using its patented TrueCal™ calibration technology. The data provides a consistent, accurate, full representation of the spectral data with superior signal-to-noise, advantages lacking from centroid data. This allows for the accurate estimation of the number of pure spectra in each chromatographic peak without the problem of overfitting. In addition, Cerno uses an advanced chromatographic peak analysis algorithm to properly guide the deconvolution using realistic and reliable chromatographic peak shapes. This novel approach is fast, minimizes overfitting which produces “false” spectra, and produces more accurate deconvolution than other approaches. In addition, this advanced modeling approach can automatically remove spectral background (e.g. column bleed) without the need for using the classic subtraction of clean baseline regions which can be tedious and problematic.
Accurate Mass Fragment Analysis
GC/ID is the only product that can provide accurate mass/spectral accuracy confirmation of the molecular ion from search results using conventional quadrupole GC/MS. In Version 2.0, this powerful confirmation tool has been extended to also identify the formula for fragment ions. This powerful feature has, until now, been only possible using more complex and expensive high resolution GC/MS such as GC/ToF or Orbitrap instruments. Fragment analysis can not only be used to confirm the conventional library search results, it can also be used to assist in the structural elucidation of unknown compounds not present in existing libraries.
Support for New NIST20 libraries and Retention Index Analysis
One of the most powerful features of GC/ID is its unique ability to automatically calculate accurate Retention Index (RI) data from your GC and quantitively match them to the RI data in commercial or user libraries. This allows, along with accurate mass data, a very high level of confidence in determining the correct library match, which can be quite ambiguous in demanding applications. Unfortunately, accurate experimental RI data are not available for all compounds. NIST20 has now added full RI coverage using a novel new RI calculation method based on advanced Artificial Intelligence (AI) modeling. This provides full coverage of RI data in the expanded NIST20 library. In addition, GC/ID can now automatically estimate RI data for compounds in user libraries (if a structure is available) allowing this powerful metric to be utilized beyond the standard NIST library.
Full Support for All Wiley GC/MS Libraries
GC/ID is now fully compatible with the world’s largest collection of EI data, including both the Wiley Registry 11, and the new Wiley Registry 12 along with the large specialty collections (e.g. Designer Drugs, Flavors and Fragrances, Pesticides, and more). GC/ID also takes advantage of Estimated RI data for these libraries as well as any experimental RI data available in the collections.
More flexible PDF Report Generation
GC/ID report generation is now easier and more powerful than ever. Easily create PDF reports automatically at the end of a processed run or after a run is reviewed by the analyst. These powerful hyperlinked reports can contain as little or as much detail as you prefer, including the summary report for each peak detected, the detailed hit list for each possible compound including the mass spectrum, overlaid library spectrum, structure, and spectral accuracy overlay of the molecular and key fragment ion(s). Detail information for each possible compound includes fragment match scores, formulas, mixture composition for spectrally overlapping ions, Double Bond Equivalent (DBE), CAS number, and more.
Improved, Expanded, and Easily Customizable Report Tables
Customizing report tables have been made easier and more powerful than ever. Over 26 calculated and measured values can be displayed including the NIST SIM Match, Reverse Match, and Probability Match scores; molecular ion spectral accuracy (SA-M), fragment ion spectral accuracy (SA-F), formula, CAS, chemical name, as well as retention index score (RIFit), unknown RI, and library RI values. Information on chromatographic peaks detected includes peak number, retention time, edges, height, area, and the number of components in co-eluting mixtures.
Open Source, Custom Scripting
Much of GC/ID was developed using open source tools written in Python, the preferred scientific programming language. As such, GC/ID’s new Rx 2.0 platform provides powerful Python scripting with examples, allowing users to customize search algorithms, automate workflow, and experiment with new methods.
Countless Other Improvements
GC/ID Version 2.0 has 100’s of other minor improvements, a list too long to be enumerated. In addition, code improvements make GC/ID more robust, reliable, and accurate than ever.