Free NIST Data Processing Software Lab for Universities - Part 11: (Advanced) Tracking Complex Coelution with AMDIS and NIST Search
- Photo: James Little: Forensic@NIST2022 Workshop: Case Study #2 (Tackling Co-elution) – Gary Mallard.
- Video: James Little: Forensic@NIST2022 Workshop: Case Study #2 (Tackling Co-elution) – Gary Mallard.
This series of instructional videos will introduce you to FREE resources for creating a gas chromatography-mass spectrometry (GC-MS) laboratory for college and graduate or even advanced high school level students. It could also be used as a self-study course. It demonstrates the power of electron ionization (EI) MS data obtained with GC-MS systems in the characterization of mixtures with computer library searches.
The NIST MS Search software and associated programs are utilized to process data and perform library searches. Two different chemical drawing programs can be employed to enter structures into the NIST program for structure searching and to determine if observed fragments are consistent with theoretical fragmentation mechanisms and isotope ratios using MS Interpreter.
Skills Demonstrated:
Videos, handouts, and resources are supplied to aid both teachers and students. Parts 1-4 could be used separately to form a more condensed lab with the most essential parts.
- Searching EI (electron ionization) spectra using the NIST search software
- Processing of EI data files using NIST/AMDIS software
- Drawing chemical structures with drawing programs for transfer to NIST program
- Searching NIST formatted libraries by structure
- Correlating structural fragments in a mass spectrum to substructure using NIST/MS Interpreter
- Creating User Libraries
FREE resources include the following:
- Instructional videos and associated handouts
- Copy of NIST17 Library Search Software
- EI GC-MS data files supplied by NIST for processing with AMDIS
- Additional EI GC-MS files
- AMDIS deconvolution software for processing GCMS data files
- NIST MS Interpreter for understanding and correlating EI fragment ions to substructures
- NIST library of 2,373 EI mass spectra
- Additional EI reference spectra in 5 free libraries (58,456 spectra/34,939 structures)
- ACD ChemSketch structural drawing program for personal and academic use
- Mass Spec Calculator Chemical Drawing Program, free, no limitations
In the eleventh part we will look at:
Tracking Complex Coelution with AMDIS and NIST Search
Gary Mallard presented an excellent talk at the Forensic@NIST 2022 Workshop that demonstrated the use of both AMDIS and the NIST Search for identifying unknowns in coeluting GCMS peaks.
I have included the following links to his talk and associated resources. It discusses several more advanced approaches.
Link to Download Talk from Google Drive
GCMS Data Files Used in the Talk
Link to All Presentations
Other parts of this series are focused on:
- Part 1: Very Basic Theory of GCMS Analyses
- Part 2: Installation of Software in Free Laboratory Resource for Universities
- Part 3: EI Mass Spec Library Searches
- Part 4: Processing GCMS Data with AMDIS
- Part 5: Understanding EI Fragments with MS Interpreter in Free Laboratory Resource for Universities
- Part 6: Structure Searches with Input from ChemSketch
- Part 7: Creating a User Library
- Part 8: Advanced Processing with NIST Software
- Part 9: 58,456 Additional Reference Spectra for NIST Demo Search
- Part 10: AMDIS Difficulties and Ways to Overcome Them
