Effective Use of EI Mass Spectral Databases in Unknown Identifications - Part IV: Advanced NIST Hybrid Search of EI and MS/MS Spectra

NIST, Wiley, and user-created EI mass spectral libraries are very powerful tools for the identification of organic compounds in complex mixtures by gas chromatography-mass spectrometry (GC-MS).  This series of webinars will demonstrate the use of the NIST software suite including the NIST Search, AMDIS, and MS Interpreter for searching EI libraries. The series should be useful to a wide variety of research and developmental scientists involved in medical, environmental, industrial, forensic, and biological disciplines.

The webinars demonstrate both Versions 3.0 (2023) and V2.4 of the NIST search. If you are using V3.0, start with Part 0. If you are using V2.4, start with Part I.

Today, we will look at:

Part IV: Advanced NIST Hybrid Search of EI and MS/MS Spectra

• Help Files for NIST Search
• General Windows commands/functions
• Program description and my personal experience
• Hybrid generates score based on both fragments and neutral losses
• Setting up indices for EI hybrid search for Wiley and user libraries
• Saving configuration for EI hybrid search
• Hybrid search results for unknown
• Tip: See normal EI identity search results in hybrid search list
• “Mentally” merge information of hybrid and simple EI identity search
• Closer look at middle display of hybrid search
• Neutral loss display of hybrid search results
• Use available accurate mass data to support nominal mass hybrid search
• Hybrid search needs nominal MW of species to work properly
• Using NIST software to obtain proposed nominal MW
• View of hit list structure hybrid search options
• DeltaMass table
• Associating some simple structures with DeltaMass values
• Other things to consider using hybrid search for unknown identification
• NIST MSMS (tandem) hybrid searches
• Additional NIST MSMS (tandem) hybrid search menus
• Wiley MSMS (tandem) libraries
• Webinar references
• Acknowledgements

Detailed Handouts including tables of content are available in the LabRulezGCMS library

Other parts of this series are focused on:

• Part 0: Changes in EI NIST23 Program (V3.0) (video only)
• Part I: Spectral Searches with NIST MS Search
• Part II: Structure Searches with MS Search and Using MS Interpreter
• Part III: AMDIS (NIST) for Processing EI Mass Spectral Data Files
• Part IV: Advanced NIST Hybrid Search of EI and MS/MS Spectra (this part)
• Part V: Creating and Sharing User EI and MS/MS Libraries
• Part VI: Creating and Using Retention Indices in NIST Software
• Part VII:  Tracking Complex Coelution with AMDIS and NIST Search

Higher quality videos can be downloaded here:

• Higher Quality Video Part 0
• Higher Quality Videos Pt. I-V Zipped

Other Webinar Resources:

• Test Files Used In Part VII for Tracking Coelution in Complex Mixtures with AMDIS and NIST
• New NIST23 Brochures and Purchasing
• NIST23 ASMS Presentation Houston, TX
• NIST 23 Separation Science Article by David Sparkman
• NIST and AMDIS User Manuals
• NIST Approach for Creating Libraries
• Databases Listed in Version 3.0 (2023)
• ACD Free Software (structure drawing program personal/academic use)
• Mass Spec Calculator Professional (free structure drawing program)
• Using with Manufacturers Data Processing Software
• Delta Mass Table (Excel Format)
• Delta Mass Table (PDF format)
• Hybrid Search/ChemSpider/SciFinder for Illicit Drug Identifications
• Importing Mass Spectra to NIST Search Program
• MS_Interpreter Correlating Structure to Spectrum
• NIST Tutorials and Settings for AMDIS
• Example Files for Part III AMDIS Webinar
• Example Spectra/Structures in Library Format Parts I-V
• Wiley Library User Manual with Spectral Source Codes
• Using with Manufacturers Data Processing Software
• Components in Free MONA Libraries
• MONA Library in EI format
• MONA and Other Free Libraries, 60,829 EI Spectra (see read_me in zip file)